Note: Descriptions are shown in the official language in which they were submitted.
20~4666
~.,
LARGE-PORED MOLECULAR SIEVES WITH CHARGED OCTAHEDRAL
TITANIUM AND CPARGED TETRAHEDRAr ALUMINUM SITES
QACKGROUND OF ~HE ~VENTION
1. Field of the Invention
This invention relates to new crystalline titanium
molecular sieve zeolite compositions, having both aluminum and
titanium in the framework structure, methods for preparing the
same uses thereof such as organic compound conversions
therewith, especially hydrocarbon conversions and in ion
exchange applications. The novel materials of this invention
owe their uniqueness to the fact that the framework titanium is
octahedrally coordinated whereas the framework aluminum is
tetrahedrally coordinated.
2. ~ackground of the Invention and Prior Art
Since the discovery by Milton and coworkers
(U. S. 2,882,243 and U. S. 2,882,244) in the late 1950's that
aluminosilicate systems could be induced to form uniformly
porous, internally charged crystals, analogous to molecular
sieve zeolites found in nature, the properties of syn~hetic
aluminosilicate zeolite molecular sieves have formed the basis
of numerous commercially important catalytic, adsorptive and
ion-exchange applications. This high degree of utility is the
result of a unique combination of high surface area and uniform
potosity dictated by the "framework" structure of the zeolite
crystals coupled with the electrostatically charged sites --~
induced by tetrahedrally coordinated Al . Thus, a large
., ' .
.- :: ' , .. ... _ .. , , ,. . ._,~
~ 2~1~666 ---
number of ~active~ charqed sites are readilv accessible to
molecules of the DroDer size and geometrv for adsorDtive or
catalytic interactions. Further, since charqe comDensatina
cations are electrostaticallv and not covalentlY bound to the
aluminosilicate framework, they are qenerally exchanaeable for
other cations with different inherent DroDerties. This offers
wide latitude for modification of active sites wherebv sDecific
adsorbents and catalvsts can be tailormade for a aiven utilitv.
In the Dublication ~Zeolite Molecular Sieves~, ChaDter
2, 1974, D. W. Breck hvDothesized that DerhaDs 1,000
aluminosilicate zeolite framework structures are theoreticallv
Dossible, but to date onlv aDDroximatelv 150 have been
identified. While comDositional nuances have been described in
Dublications such as U. S. 4,524,055, U. S. 4,603,040 and U. S.
4,606,899, totallv new aluminosilicate framework structures are
beina discovered at a nealiqible rate. Of Darticular
imDortance to fundamental Droaress in the catalvsis of
relativelv larqe hvdrocarbon molecules, especiallv fluid
crackina operations, is the fact that it has been a aeneration
since the discoverv of anv new larqe Dored aluminosilicate
zeolite.
With slow Droaress in the discoverv of new wide Dored
aluminosilicate based molecular sieves, researchers have taken
various aDDroaches to reDlace aluminum or silicon in zeolite
svnthesis in the hoDe of aeneratinq either new zeolite-like
framewor~ structures or inducina the formation of qualitativelv
different active sites than are available in analoaous
aluminosilicate based materials. While Droaress of academic
~ 201~666
interest has been made from different aDDroaches, little
success has been achieved in dis~overina new wide Dore
molecular sieve zeolites.
It has been believed for a aeneration that DhosDhorus
could be incorDorated, to varvina dearees, in a zeolite tyDe
aluminosilicate framework. In the more recent Dast (JACS 104
DD. 1146 (1982) Proceedinqs of the 7th International Zeolite
Conference, DD. 103-112, 1986) E. M. Planiaan and coworkers
have demonstrated the DreDaration of oure aluminoDhosDhate
based molecular sieves of a wide variety of structures.
However, the site inducina Al 3 is essentiallv neutralized by
the P+5, imDartina a +l charae to the framework. ThUs, while
a new class of ~molecular sieves~ was created, thev are not
zeolites in the fundamental sense since they lack ~active~
charaed sites.
Realizina this inherent utilitv limitina deficiencv,
for the Dast few vears the molecular sieve research community
has emDhasized the synthesis of mixed aluminosilicate-metal '~
oxide and mixed aluminophosDhate-metal oxide framework
systems. While this aDDroach to overcomina the slow Droaress
in aluminosilicate zeolite synthesis has qenerated
aDDroximately 200 new com w sitions, all of them suffer either
from the site removina effect of incorDorated P 5 or the site
dilutina effect of incorDoratina effectively neutral
tetrahedral +4 metals into an aluminosilicate tvDe framework.
As a result, extensive research by the molecular sieve research
communitv has failed to demonstrate sianificant utility for any
of these materials.
..,..
., ,, ~
~- 20~666
A series of zeolite-like ~framework~ silicates have
been synthe~ized, some of which llave larger uniform pores than
are observed for aluminosilicate zeolites. (W. M. Meier,
Proceedinas of the 7th International Zeolite Conference,
DD. 13-22 (1986).) While this particular synthe-ci~ approach
oroduces materials which, bv definition, totallv lack active,
charaed sites, back imDlementation after svnthesis would not
aDDear out of the question althou~h little work apDears in the
open literature on this topic.
Another and most straiahtforward means of Dotentiallv
aeneratina new structures or qualitativelv different sites than
those induced bv aluminum would be the direct substitution of
some other charae inducina sDecies for aluminum in zeolite-like
structures. To date the most notablv successful examole of
this aDDroach aoDears to be boron in the case of ZSM~ 5 analoas,
althouah iron has also been claimed in similar materials. (EPA
68,796 (1983), Taramasso et al; Proceedinas of the 5th
International Zeolite Conference: oo. 40-48 (1980)); J. w. 3all
et al: Proceedinas of the 7th International Zeolite Conference:
DD. 137-144 (1986) U. S. 4,280,305 to Kouenhowen et al.
Unfortunatelv, the low levels of incorporation of the species
substitutina for aluminum usually leaves doubt if the species
are occluded or framework incorporated.
In 1967, Youna in U. S. 3,329,481 reDorted that the
svnthesis of charae béariria (exchanaeable) titanium silicates
under conditions similar to aluminosilicate zeolite formation
was possible if the titanium was Dresent as a "critical
reaaent~ +III Deroxo soecies. While these materials were
._ ~
20~666
called ~titanium zeolites~ no evidence was Dresented bevond
some questionable X-ray diffraction ~XRD) Datterns and his
claim has qenerally been dismissed bv the zeolite research
communitv. (D. W. 3reck, Zeolite Molecular Sieves, D. 322
~1974); R. M. Barter, Hvdrothermal Chemistrv of Zeolites,
D. 293 (1982); G. Pereao et al, Proceedinas of 7th
International Zeolite Conference, D. 129 (1986). ) For all but
one end member of this series of materials (denoted TS
materials), the Dresented XRD Datterns indicate Dhases too
d?nse to be molecular sieves. In the case of the one
questionable end member (denoted TS-26), the XRD Dattern miqht
Dossiblv be interDreted as a smaIl Dored zeolite, althouah
without additional suDDortina evidence, this aDDears extremelv
questionable.
A naturallv occurrina alkaline titanosilicate
identified as ~Zorite~ was discovered in trace quantities on
the Kola Peninsula in 1972 ( A. N. Mer'kov et al; ZaDiski Vses
Mineraloq. Obshch., Paaes 54-62 (1973), The Dublished XRD
Dattern was challenaed and a DroDosed structure reDorted in a
later article entitled ~The OD Structure of Zorite",
Sandomirskii et al, Sov. Phvs . Crvstallocr. 24 ( 6), Nov-Dec
1979, Daaes 686-693.
No further reDorts on ~titanium zeolites~ apDeared in
the open literature until 1983 when trace levels of tetrahedral
Ti(IV) were reDorted in a ZSM-5 analoq. (M. Taramasso et al;
U. S. Patent 4,410,501 (1983); G. Pereao et al; Proceedinas of
the 7th International Zeolite Conference; D. 129 (1986).~ A
similar claim aDDeared from researchers in mid-1985 (EPA
_.. ,, ~'
.
.,.. ,. ~
2014666
-
132,550 (1985).) More recently, the research community
reported mixed aluminosilicate-titanium(IV) (EPA 179,876
(1985); EPA 181,884 (1985) structures which, along with
TAPO (EPA 121,121 (1985) systems, appear to have no
possibility of active titanium sites because of the
titanium coordination. As such, their utility is highly
questionable.
That charge bearing, exchangeable titanium silicates
are possible is inferred not only from the existence of
exchangeable alkali titanates and the early work
disclosed in U. S. 3,329,481 on ill defined titanium
silicates but also from the observation (S.M.Kuznicki et
al; J. Phys. Chem.; 84; pp. 535,537 (1980) of Tio4 - units
in some modified zeolites.
David M. Chapman, in a speech before 11th North
American Meeting of the Catalysis Society in Dearborn,
Michigan (1989) gave a presentation wherein a titanium
aluminosilicate gel was crystallized with Chapman
claiming all the aluminum was segregated into analcime
(an ultra-small pored aluminosilicate) and not
incorporated into any titanium-bearing phase such as his
observed analog of the mineral vinogradovite which was a
pure titanium silicate. It is noted that vinogradovite,
as found in nature, has been reported to contain
aluminum. However, neither the synthetic analog of
vinogradovite nor the mineral vinogradovite is a
molecular sieve nor does it have the x-ray diffraction
pattern of Table I of this specification.
A major breakthrough in the field of large pored
titanium silicate molecular sieves is disclosed and
claimed in U.S.Patent 4,853,202. The crystalline
titanium silicate large pored molecular sieve of said
patent, hereafter designated ETS-10, contains no
deliberately added alumina but may contain very minor
amounts of alumina due to the presence of impurities.
Thus, ETS-10 typically have a molar ratio of SiO2/A1203
greater than 100 or more.
--6--
~; ~
2014666
SUMMARY OF THE INVENTION
The present invention relates to a new family of
stable, large pore crystalline titanium-aluminum-silicate
molecular sieves, hereinafter designated ETAS-10, their
method of preparation and the use of such compositions as
absorbents, catalysts for the conversion of a wide
variety of organic compounds, e.g., hydrocarbon compounds
and oxygenates such as methanol as well as ion-exchangers
for the removal of undesirable metal cations from
solutions containing the same.
Another aspect of this invention is as follows:
A crystalline titanium-aluminum-silicate molecular
sieve having a large pore size of approximately 9
Angstrom units and having a composition in terms of mole
ratios of oxides as follows:
(l+x) (1.0 + 0.25 M2/n 0): Tio2 : x A10z : y Si02 : z H20
wherein M is at least one cation having a valence of n, y
is from 2.5 to 25, x is from 0.01 to 5.0 and z is from 0
to 100, said molecular sieve being characterized by a)
having an X-Ray powder diffraction pattern as hereinafter
set forth:
TABLE 1
(0 - 40~2 theta)
SIGNIFICANT d-SPACING (ANGS.) I/Io
14.7 - .50 + 1.0 W-M
7.20 +.15 (optional) W-M
4.41 -.05 + 0.25 W-M
3.60 -.05 + 0.25 VS
3.28 -.05 + .2 M-S
30 wherein:
VS = 60-100
S = 40-60
M = 20-40
W = 5-20,
b) having mono-charged tetrahedrally coordinated aluminum
in the framework, and c) having di-charged octahedrally
coordinated titanium in the framework.
--7--
2014666
Other aspects of the invention involve a process for
conversion of an organic compound which comprises
contacting the same at conversion conditions with the
composition set out above; a process for catalytic
s cracking of hydrocarbon which comprises contacting the
same with the composition set out above at elevated
temperatures; a process for reforming a naptha which
comprises contacting the same in the presence of added
hydrogen and a hydrogenation/dehydrogenation component
with the composition set out above; and a process for the
removal of divalent ions from a solution containing the
same which comprises contacting the solution with the
composition set out above.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a new family of
stable crystalline titanium-aluminum-silicate molecular
sieve which have a pore size of approximately 9 Angstrom
units. These titanium-aluminum-silicates have a definite
X-ray diffraction pattern and can be identified in terms
of mole ratios of oxides as follows:
(l+x) (1.0 + 0.25 M2~n ~): TiOz: x A102 : y SiO2 : z H2 ~
wherein M is at least one cation having a balance of n, y
is from 2 . 0 to 100, x is from 0.05 to 5.0 and z is from O
to 100. In a preferred embodiment, M is a mixture of
alkali metal cations, particularly sodium and potassium,
and y is at least 3.0 and ranges up to about 10.
-7a-
~- 2014666
The original cations M can be replaced at least n part
with other cations by well known exchange techniques. Preferred ~--
replacing cations include hydrog~n, ammonium, rare earth, and
mixtures thereof. ~embers of the family of molecular sieve
zeolites designated ETAS-10 have a high degree ~f thermal
stability of at least 450~C or higher, thus rendering them
effective for use in high temperature catalytic processes.
ETAS-10 zeolites are highly adsorptive toward molecules up to
approximately 9 Angstroms in critical diameter such as
1,3,5-trimethylbenzene. In the sodium form, ETAS-10 is completely
reversibly dehydratable with a water capacity of approximately 20
weight percent.
Members of the ETAS-10 family of molecular sieve zeolites
have a crystalline structure and an X-ray powder diffraction
pattern having the following significant lines:
TABLE 1
XRD POWDER PATTERN OF ETAS-ln
(0 - 40~ 2 theta)
SIGNIFICANT d-SPACING (ANGS.) I/I
14.7 - .50 + 1.0 W-M
7.20 + .15 (optional) W-M
4.41 - .05 + 0.25 w-M
3.60 - .05 + 0.25 VS
3.28 - .05 + .2 M-S
In the above table,
VS = 60-100 --
S 5 40-60 --~
M - 20-40 -
W = 5-20
The above values were determined by standard x-ray
diffraction techniques. The radiation was the K-alpha doublet
- ,~ ,
,
2014666
-
of copper, and a scintillation counter spectrometer was
used. The peak heights, I, and the positions as a
function of 2 times theta, where theta is the Bragg
angle, were read from the spectrometer chart. From
these, the relative intensities, 100 I/Io, where Io is the
intensity of the strongest line or peak, and d (obs.),
the interplanar spacing in angstroms, corresponding to
the recorded lines, were calculated. These interplanar
d-spacings define the crystalline structure of the
particular composition. It has been determined that the
X-ray powder diffraction peaks characteristics of ETS-10
are systematically altered by the inclusion of increasing
amounts of aluminum addition in ETAS-10. Such systematic
alterations are taken as prima facie evidence of
framework incorporation of some newly introduced species
much akin to classical zeolite synthesis. As pointed out
in U. S. patent 4,853,202 ETS-10 contains the most
significant lines which are set forth as follows:
TABLE 2
20ETS-10 CHARACTERISTIC d-SPACINGS
d-SPACINGS (ANGS.) I/Io
14.7 + 0.35 W-M
7.20 i 0.15 W-M
4.41 + 0.10 W-M
3.60 + 0.05 VS
3.28 + 0.05 W-M
It has been found that as the degree of aluminum
incorporation increases in ETAS-10, the largest d-spacing
analogous to 14.7 A in ETS-10 and the strongest
characteristic d-spacing analogous to 3.60 A in ETS
markedly increase. In
201466~
,.,
fact, as hiaher levels of aluminum inCorDOratiOn are attained,
the increase of these lines falls outside the claim limits for
ETS-10. Additionally, one of the characteristic d-sDacinas
7.20 A disapDears. However, it is not known at this time if
the disapDearance reDre~ents a structural chanae or if it i~
morDholoaically induced.
Althouah ETAS-10 i9 structurallv related to ETS-10,
in'troduction of substantial quantities of hiahlv Dolar
mono-charaed tetrahedral aluminum ~ites into the zeolitic
framework Drofoundlv alters the character of the sieve,
imDactina adsorDtive, ion-exchanae and 'catalytic DroDerties.
ETAS-10 can be clearlv and easily differentiated from ETS-10 by
standard analytical techniques such a~ NMR and in some cases by
X-ray diffraction.
While structurally related to ETS-10, incorDoration of
aluminum into the framework structure Oe ETAS-10 svstematically
exDands the lattice Dlanes and Dore oDeninas. This in turn
allows ETAS-10 to sorb molecules somewhat laraer than those
sorbed by ETS-10. Additionally, the sorbtive DroDerties are
transformed from a relativelv weak to a stronaer sorbant and
much more Dowerful ion-exchanaer. The ion exchanae DroDerties
are altered in such a manner that certain heavv metals,
esDecially lead, are evacuated from aqueous solutions
essentiallv on contact. The incorporation of aluminum into the
framework also makes the catalvtic acidity of ETAS-10
substantiallv difFerent than that of ETS-10 in that it is verv
strona, capable of crackina alkanes as would be exDected Crom
zeolitic aluminum sites but the hiqh alkene yield
characteristic of relativelv weak octahedral sites is eetained.
-- 10 --
.; .
.
2014666
,~ ~ '" "
It is to be immediately understood that appiicants are
not maintaining to be the first to have prepared a molecular
sieve containing titanium, aluminum and silicon in significant
amounts. Materials of this type have previously been reported
in the TASO work of Lok, EPO 181,884 and EPO 179,876 previously
referred to. However, in both the specifications and claims of
these patents, it is clearly stated that the silicon, titanium
and aluminum are tetrahedral with the titanium being therefore
uncharged. The crystal structures of the instant invention on
- the other hand, have di-charged octahedrally coordinated
titanium in combination with mono-charged tetrahedrally
coordinated aluminum sites.
- ETAS-10 molecular sieves can be prepared frlom a
reaction mixture containing a titanium source such as titanium
trichloride with an aluminum source such as aluminum chloride,
a source of silica, a source of alkalinity such as an alkali
metal hydroxide, water and, optionally, an alkali metal
fluoride mineralizer having a ComDOSitiOn in terms of mole
ratios falling within the following ranges.
TABLE 3
Broad Preferred Most Preferred
SiO2/A1 1-200 2-100 2-20
SiO2/Ti 2-20 3-10 4-7
H2O/siO2 2-100 5-50 10-25
Mn/SiO2 0.1-20 0.5-5 1-3
wherein M indicates the cations of valence n derived from the -
alkali metal hydroxide and potassium fluoride and/or alkali
metal salts used for preparing the titanium silicate according
to the invention. The reaction mixture is heated to a
4 ~
~, ~
201~666
~,
temperat re of from about 100~C to 250~C for a period of time
ranging from about 2 hours to 40 days, or more. The
hydrothermal reaction is carried out until crystals are formed
and the resulting crystalline product is thereafter separated
from the reaction mixture, cooled to room temperature, filter*d
and water washed. The reaction mixture can be stirred although
it is not necessary. It has been found that when using gels,
stirring is unnecessary but can be employed. When using
s~urces of titanium which are solids, stirring is beneficial.
The preferred temperature range is 150~C to 225~C for a period
of time ranaing from 4 hours to 4 days. Crystallization is
performed in a continuous or batchwise manner under a~utogenous
pressure in an autoclave or static bomb reactor. Following the
water washing step, the crystalline ETAS-10 is dried at
temperatures of 100 to 600~F for periods up to-30 hours.
The method for preparing ETAS-10 compositions
comprises the preparation of a reaction mixture constituted by
sources of silica, sources of alumina, sources of titanium,
sources of alkalinity such as sodium and/or potassium oxide and
water having a reagent molar ratio composition as set forth in
Table 3. Optionally, sources of fluoride such as potassium
fluoride can be used, particularly to assist in solubilizing a
solid titanium source such as Ti2O3. However, when
titanium aluminum silicates are prepared from gels, its value
is diminished.
The silica source-includes most any reactive source of
silicon such as silica, silica hvdrosol, siiica gel, siiicic
acid, alkoxides of silicon, alkali metal silicates, preferably
sodium or potassium, or mixtures of the foregoing.
' ' '~
2014666
The titanium oxide sour~e is trivalent or tetravalent
and compounds such as titanium trichloride, TiC13, or
titanium tetrachloride, TiC14 can be used.
The aluminum source can include sodium aluminate,
aluminum salts such as aluminum chloride, etc.
The source of alkalinity is preferably an aqueous
solution of an alkali metal hydroxide, such as sodium
hydroxide, which provides a source of alkali metal ions for
maintaining electrovalent neutrality and controlling the pH of
the reaction mixture within the range of 10.0 to 11.5. As
shown in the examples hereinafter, pH is critical for the
production of ETAS-10. The alkali metal hydroxide serves as a
source of sodium oxide which can also be supplied by an aqueous
solution of sodium silicate.
The crystalline titanium-aluminum-silicates as
synthesized can have the original components thereof replaced
by a wide variety of others according to techniques well known
in the art. Typical replacing components would include
hydrogen, ammonium, alkyl ammonium and aryl ammonium and
metals, including mixtures of the same. The hydrogen form may
be prepared, for example, by substitution of original sodium
with ammonium or by the use of a weak acid. The composition is
then calcined at a temperature of, say, 1000~F causing
evolution of ammonia and retention of hydrogen in the
composition, i.e., hydrogen and/or decationized form. Of the
replacing metals, pref~rence is accorded to metals of Groups
II, IV ana VIII of the ~eriodic Table, preferably the rare
earth metals.
'
20~666
.,
The crystalline titanium-aluminum-silicates are then
preferably washed with water and dried at a temperature ranging
from about 100~F to about 600~F and thereafter calcined in air
or other inert gas at temperatures ranging from 500~F to 1500~F
for periods of time ranging from l/2 to 48 hours or more.
Regardless of the synthesi2ed form of the titanium
silicate the spatial arrangement of atoms which form the basic
crystal lattices remain essentially unchanged by the
replacement of sodium or other alkali metal or by the presence
in the initial reaction mixture of metals in addition to
sodium, as determined by an X-ray powder diffract-on pattern of
the resulting titanium silicate. The X-ray diffraction
patterns of such products are essentially the same as those set
forth in Table I above (with the exception that the
7.20 ~ .15 A line is sometimes not observed).
The crystalline titanium-aluminum-silicates prepared
in accordance with the invention are formed in a wide variety
of particular sizes. Generally, the particles can be in the
form of powder, a granule, or a molded product such as an
extrudate having a Particle size sufficient to pass through a 2
mesh (Tyler) screen and be maintained on a 400 mesh (Tyler)
screen in cases where the catalyst is molded such as by
extrusion. The titanium silicate can be extruded before drying
or dried or partially dried and then extruded.
When used as a catalyst, it is desired to incorporate
the new crystalline titanium-aluminum-silicate with another
mater-al resistant ~o the temperatures and other -onditicns
employed in organic processes. Such materials include active
- 14 -
201~666
~' ,
and inactive materials and synthetic and naturally
occurring zeolites as well as inorganic materials such as
clays, silica and/or metal oxides. The latter may be
either naturally occurring or in the form of gelatinous
precipitates or gels including mixtures of silica and
metal oxides. Use of a material in conjunction with the
new crystalline titanium silicate, i.e., combined
therewith which is active, tends to improve the
conversion and/or selectivity of the catalyst in certain
organic conversion processes. Inactive materials
suitably serve as diluents to control the amount of
conversion in a given process so that products can be
obtained economically and in an orderly manner without
employing other means for controlling the rate of
reaction. Normally, crystalline materials have been
incorporated into naturally occurring clays, e.g.,
bentonite and kaolin to improve the crush strength of the
catalyst under commercial operating conditions. These
materials, i.e., clays, oxides, etc., function as binders
for the catalyst. It is desirable to provide a catalyst
having good crush strength because in a petroleum
refinery the catalyst is often subjected to rough
handling which tends to break the catalyst down into
powder-like materials which cause problems in processing.
These clay binders have been employed for the purpose of
improving the crush strength of the catalyst.
Naturally occurring clays that can be composited
with the crystalline titanium silicate described herein
include the smectite and kaolin families, which families
include the montmorillonites such as sub-bentonites and
the kaolins in which the main constituent is kaolinite,
hallovsite, dickite, nacrite or anauxite. Such clays can
be used in the raw state after conventional gritting or
they can be subjected to additional processing such as
calcination, acid treatment or chemical modification.
In addition to the foregoing materials, the
crystalline titanium silicate may be composited with
-15-
X
'~ :
~ '
: .
; ~ ~; !
~, '
..~
2~1~666
matrix materials such as silica-alumina, silica-magnesia,
silica-zirconia, silica-thoria, silica-berylia, silica-
titania as well as ternary compositions such as silica-
alumina-thoria, silica-alumina-zirconia, silica-alumina-
magnesia and silica-magnesia-zirconia. The matrix can be
in the form of a cogel. The relative proportions of
finally divided crystalline metal organosilicate and
inorganic oxide gel matrix can vary widely with the
crystalline organosilicate content ranging from about 1
to 90 percent by weight and more usually in the range of
about 2 to about 50 percent by weight of the composite.
As is known in the art, it is often desirable to
limit the alkali metal content of materials used for acid
catalyzed reactions. This is usually accomplished by ion
exchange with hydrogen ions or precursors thereof such as
ammonium and/or metal cations such as rare earth.
Employing the catalyst of this invention, containing
a hydrogenation component, heavy petroleum residual
stocks, cycle stocks, and other hydrocrackable charge
stocks can be hydrocracked at temperatures between 400~F
and 825~F using molar ratios of hydrogen to hydrocarbon
charge in the range between 2 and 80. The pressure
employed will vary between 10
~r
201g666
and 2,500 DSiq and the liquid hourlv space velocity between 0.1
and 10.
EmDloyina the catalvst of t~is invention for catalytic
cracking, hydrocarbon crackina stocks can be cracked at a
liquid hourly sDace velocity between about 0.5 and 50, a
temDerature between about 550~F and llOn~F, a pressure between
about suDatmosDheric and several hundred atmosDheres.
EmDloyina a catalytically active form of a member of
the family of zeolites of this invention containina a
hydroaenation comDonent, reformina stocks can be reformed
emDloyina a temDeratUre between 700~F and 1000~F. The Dressure
can be between 100 and 1,000 psig, but is Dreferably between
Z00 to 700 Dsiq. The liquid hourlv sDace velocitv is generallv
between 0.1 and 10, Dreferablv between 0.5 and 4 and the
hydrogen to hydrocarbon mole ratio is generally between 1 and
20, Dreferably between 4 and 12.
The catalyst can also be used for hvdroisomerization
of normal Daraffins when provided with a hydroaenation
comDonent, e.g., olatinum. Hvdroisomerization is carried out
at a temperature between 200~ and 700~F, preferablv 300~F to
550~F, with a liquid hourlv sDace velocity between 0.01 and 2,
Dreferably between 0.25 and 0.50 employina hydro~en such that
the hydrogen to hydrocarbon mole ratio is between 1:1 and 5:1.
Additionally, the catalyst can be used for olefin isomerization
employina temDeratUreS between 30~F and 500~F.
In order to more fullv illustrate the nature of the
invention and a manner of Dracticina the same, the following
examDles illustrate the best mode now contemplated.
-- 17 --
2~1~6~
!~
.
Because of the difficulty of measuring pH during
crystallization, it is to be understood that the term pR as
used in the specification and claims refers to the p~ of the
reaction mixture before crystallization diluted 100:1 by weight
with water and equilibrated for periods of time ranging from
5-20 minutes.
EXAMPLE 1
A large lot of ETS-10-type gel was prepared for
attempted direct aluminum incorporation. 1,256 g of ~ 8rand
sodium silicate solution was thoroughly mixed and blended with -~'
179 g NaOH and 112 g KF (anhydrous) to form an alkaline
silicate solution. To this solution was added 816 g of
commercial Fisher titanous chloride solution which was
thoroughly mixed and blended with the previous solution using
an overhead stirrer. After mixing and initial gel formation,
110 g NaCl and 10 g of calcined ETS-10 seed crystals were added
and thoroughly blended into the gel. The "pH" of the gel,
using our standard 100:1 dilution, after a 5 min. equilibration
period was found to be approximately 10.05, an appropriate
level for ETS-10 formation if TiC13 is employed as the
titanium source. ~ -~~
A small portion of the ETS-10 type gel (8-lOg) was
removed from the large lot and crystallized at autogenous
pressure for 24 hours at 200~C. ~ crystalline product was
obtained which, after washing and drying demonstrated a small
amount of an impurity believed to be ETS-4 (~15%) and a
dominant phase with the following characte!istic YRD lines:
d-spacing (Angstroms) I/I
14.7 W-~
7.19 W-M
4.40 w- M
3.60 VS
3.28 W-M
- 18 -
.--
.. . . . . ....
201~66~
EXAMPL~ 2
A suspension of potassium fluoride in an alkaline
silicate solution was prepared from the following reactants: -
502.4 g N~ brand sodium-silicate
80.0 g NaOH
46.4 g KF (anhydrous)
A mixed Al/Ti solution was prepared from the following
reactants:
326.4 g Fisher TiC13 solution
12.8 g AlC13 6H2o
To the alkaline silicate solution was slowly added the
mixed Al/Ti solution while thoroughly blending us ing an
overhead stirrer and to the resultant apparently homogeneous
gel was added 30 g NaCl and 4 g of calcined ETS-10 seed
crystals and mixing continued until the mixture again appeared
homogeneous.
The seeded titanium-aluminum-silicate reactant mixture
was autoclaved without stirring under autogenous pressure for
24 hours at 200~C. In this example, the Al/Ti ratio in the
reactant mixture was prepared to be 1/8. A crystalline product t
was obtained whose air-equilibrated d-spacings corresponding to
those of Table 1 were:
d-spacing (Angstroms) I/Io
14.85 W-M
.21 . W-M
4.42 ~-M
3.61 VS
3.28 M-S
A general upshift in d-spacings, especially on the
highest d-spacing was noted in comparison to Table 2 (~TS-10).
-- 19 -- "~
~.,
~.
201~66~
",
EXAMPLE 3
Following the procedure of Example 2 an alkaline
silicate solution was prepared from the following
reactants:
502.4 g N brand sodium-silicate
88.3 g NaOH
46.4 g KF (anhydrous)
A mixed Al/Ti solution was prepared from the
following reactants:
326.4 g Fisher TiCl3 solutions
25.6 g AlC13 ~ 6H20
The alkaline silicate and the mixed Al/Ti solution
were thoroughly blended using an overhead stirrer and to
the resultant gel was added 20 g NaCl and 4 g of calcined
ETS-10 seed crystals.
The seeded titanium-aluminium-silicate reactant
mixture was autoclaved under autogenous pressure for 24
hours at 200~C. In this example, the Al/Ti ratio in the
reactant mixture was prepared to be 1~. A crystalline
product was obtained whose air-equilibrated d-spacings
corresponding to those of Table 1 were:
d-spacing (Angstroms) I/Io
14.88 W-M
7.22 W
4-45 W-M
3.61 VS
3.285 M-S
-20-
20146~6
Aqain, several of the d-spacings demonstrate a
measurable upshift in comparison to both the prior example with '
lower aluminum addition as well as the ETS-10 of Table 2.
EXAMPLE 4
Following the general procedure of EXam~le 2 an
alkaline silicate solution was prepared from the following
reactants:
502.4 g ~ brand sodium-silicate
96.6 g ~aOR
46.4 g KF (anhydrous)
A mixed Al/Ti solution was prepared from the following
reactants:
- - 326.4 g Fisher TiC13 solution
38.4 a ~lC13~6~20
The alkaline silicate and the mixed Al/Ti solution
were thoroughly blended using an overhead stirrer and to the
resultant gel was added 10 g NaCl and 4 g of calcined ETS-10
seed crystals.
The seeded titanium-aluminum-silicate reactant mixture
was autoclaved under autogenous pressure for 24 hours at
200~C. In this example, the Al/Ti ratio in the reactant
~.
201~6~
mixture was prepared to be 3/&. A crystalline product was
obtained whose air equilibrated d-spacings corresponding to
those of Table 1 were:
d-spacing ~Angstroms) I/I
14.97 W-M
(7.2 no longer observed)
4.44 ~-M
3.~3 vs
3.30 M-S
Again, several of the d-spacings demonstrate a
measurable upshift in comparison to both the prior examples
with lower aluminum addition as well as the ETS-10 of Table 2.
The peak at 7.2 A associated with E~S-10 is no longer observed.
EXAMPLE 5
An alkaline silicate solution was prepared from the
following reactants:
502.4 g ~ brand sodium-silicate
105.0 9 NaOH
46.4 g KP (anhydrous~
A mixed Al/Ti solution was prepared from the following
reactants:
326.4 g Fisher TiC13 solution
51.2 g AlC13~6~20
The alkaline silicate and the mixed Al/Ti solution
were thoroughly blended using an overhead stirrer and to the
resultant gel was added 4 g of calcined ~TS-l~ seed crvstals.
The seeded titanium-aluminium-silicate reactant
mixture was autoclaveq under autogenous pressure for 24 hours
at 200~C. In this example, the Al/Ti ratio in the reactant
mixture was prepared to be 1/2. A crystalline product was
- 22 -
2014666
.~
obtained whose air-equilibrated d-cpacings corresponding to
those of Table 1 were:
d-spacing (A) I/I
14.97 22
(7.2 no longer observed),
5.05 6
4'45 10
3.78 7
3.~5 10
3.31 39
2.59 18
2.53 42
2.49 16
Again, several of the d-spacings demonstrate a
measurable upshift in comparison to both the prior examples
with lower aluminum addition as well as the ETS-10 of Table 2.
The peak at 7.2 .~ associated with ETS-10 is again no longer -
observed.
EXAMPLE 5
An alkaline silicate solution was prepared from the
following reactants:
502.4 g ~1 brand sodium-silicate
121.7 g MaOH
46.4 g K~ (anhydrous)
A mixed Al/Ti solution was prepared from the following
reactants:
326.4 g Fisher TiC13 solution
76.8 g AlC13.6H20
~ he alkaline silicate and the mixed Al/Ti solution
were thoroughly blended using an overhead stirrer and to the
resultant gel was added 4 g of calcined ETS-10 seed crystals.
~ ~ ,
201966~
.
The seeded titanium-aluminium-silicate reactan~
mixtu~e was autoclaved under autogenous pressure for 24 hours
at 200 C. In this example, the Al/Ti ratio in the reactant
mixture was prepared to be 3/4. A crystalline product was
obtained whose air-equilibrated d-spacings corresponding to
those of Table 1 were: ,
d-spacing (AngstromS) I/I
15.06 W-~
(7.2 no longer observed)
4.46 ~-M
3.67 vs
3 33 M-S
The XRD spectrum has now upshifted to the point where
the d-spacings for both the highest (now 15.06 A) and strongest
(now 3.67 A) peaks are no longer within the limits specified
for the ETS-10 of Table 2. The peak at 7.2 A associated with
ETS-10 is again no longer observed.
EXA~PLE 7
An alkaline silicate solution was prepared from the
follow ing reactants:
502.4 g ~ brand sodium-silicate
138.4 q NaOH
46.4 g KF (anhydrous)
A mixed Al/Ti solution was prepared from the following
reactants:
~26.4 g ~isher ~iC13 solution
102.4 g AlC13- 6H20
The alkaline 6ilicate and the mixed Al/Ti solution
were thorough!y blended using an over~.ead stirrer and to the
resultant gel was added 4 g of calcined ETS-10 seed crystals.
-- 24 --
' ' ' r~
2014666
.
-
The seeded titanium-aluminium-silicate reactant
mixture was autoclaved under autogenous pressure for 24
hours at 200~C. In this example, the Al/Ti ratio in the
reactant mixture was prepared to be 1/1. A crystalline
product was obtained whose air-equilibrated d-spacings
corresponding to those of Table 1 where:
d-spacing (Angstroms) I/Io
15.25 15
(7.2 no longer observed)
105.07 23
4.455 10
3.89 18
3.68 100
3.~3 41
152.587 24
2.536 40
2.507 25
The XRD spectrum has again upshifted to the point
where the d-spacings for both the highest (now 15.25 A)
and strongest (now 3.68 A) peaks are no longer within the
limits specified for the ETS-10 of Table 2. The peak at
7.2 A associated with ETS-10 is again no longer observed.
CONCLUSIONS FROM EXAMPLES 1-7
The systematic addition of aluminum to ETS-10-like
synthesis mixtures results in a systematic increase in
the interplanar d-spacings to the point where at
sufficient aluminum levels both the largest and the
strongest d-spacings rise above the limits for ETS-10 as
claimed. Such systematic increases are not only grossly
in excess of potential analytical error but are taken as
prima facie evidence of elemental framework incorporation
in classical zeolite synthesis.
-25-
2014666
As in the case of all other titanium bearing
molecular sieves that we have observed, phase formation
of ETAS-10 is pH dependent. In the case of ETAS-10, the
appropriate range of pH for formation is dependent on
degree of desired aluminum incorporation. At most levels
of aluminum incorporation, ETS-4 (described and claimed
in U.S. Patent No. 4,938,939) would form if aluminum were
not present. The pH utilized for ETAS formation is
higher than the level associated with ETS-10 formation.
The increased pH allowed with aluminum present allows
ETAS-10 to be grown much faster and potentially at lower
temperatures than can be accomplished for ETS-10. The pH
levels of examples 1-8 are presented as Table 4.
TABLE 4
"pH" of ETAS-10 FORMING REACTANT GELS
(10 MIN. EQUILIBRATION)
EXAMPLE "pH"
1 (ETS-10 10.10 + .03
2 10.30 + .03
3 10.35 + .03--------
4 10.55 + .03
10.65 + .03 (REGION
6 10.80 + .03 OF ETS-4
7 10.85 + .03 FORMATION
IF NO
ALUMINUM
IS PRESENT
8 10.80 _ .03
EXAMPLE 8
In this example, all pertinent reactants (alumina,
titania and silica) employed in examples 1-7 are
replaced. The gross reacion ratios resemble example 7
(i.e., the reactant Al/Ti = 1).
-26-
E
2014666
An alkaline silicate solution was prepared by
blending the following reactants;
280g sodium-disilicate solution (SDS)
45.0 g NaOH
23.2 KF (anhydrous)
30.0 g D.I. H2O
To this solution is slowly added 192.0 g of a 1.27
molal TiCl4 solution in 20 wt.% HC1. After blending, a
gel was formed to which 20 g sodium aluminate was added
and blended. The resultant mixture was autoclaved under
autogenous pressure at 200~C for 24 hours and a
crystalline product was obtained whose relevant XRD lines
were compared to the product of example 7, prepared using
different silica, titania and alumina sources. The
comparison of these patterns indicates essentially
identical ETAS-10 products.
PRODUCT OF EXAMPLE 7PREDUCT OF EXAMPLE 8
d-SPACING A (I/Io) d-SPACING (A) I/Io
15.25 W-M 15.25 W-M
20 (7.2 no longer observed)
4.45 W-M 4.45 W-M
3.68 VS 3.68 VS
3.33 M-S 3.33 M-S
This example demonstrates that ETAS-10 may be
prepared from various silica, tatinum and aluminum
sources.
EXAMPLE 9
This example establishes that as the aluminum
content of the ETAS-10 reaction mixture rises, the
aluminum content of the gross product rises proportion-
ally. As is common in molecular sieve synthesis, the
crystalline product of examples 1-8 contained mixed
phases, with ETAS-10 phases predominating (examples 2-8).
The most common contaminant noted was ETS-4.
-27-
.~
2014666
Several samples washed and dried (from examples 1,
2, 5 and 7) which contained a preponderance (estimated at
>85%) of the desired crystalline phase were analyzed by
X-ray fluorescence to determine the composition of the
gross product.
This analysis revealed:
Al/Ti AI/ti
PRODUCT OF WT.%81203 (REACTANTS) GROSS PRODUCT
EXAMPLE 1 0.28 O* 0.02
EXAMPLE 2 1.26 0.125 0.10
EXAMPLE 5 3.89 0.500 0.33
EXAMPLE 7 9.70 1.00 0.88
* = other than reactant impurities
It is common in zeolite synthesis that the incorpo-
ration of an added element is not necessarily linear with
addition. However, incorporation often appears as a
linear function of the ratios of several reactants.
This example establishes that added aluminum is
substantially integrated into the gross reaction product
of ETAS-10 synthesis mixtures. In all cases, the
exchangeable cationic content of the reaction products
approximated 2 (Ti) + 1 (Al).
Thus, if titanium (Ti) bears a charge of -2 and
aluminum (Al) bears a charge of -1, the ratios of
counter-balancing cations to 2 times the titanium content
plus 1 times the aluminum content and should approach 1.0
in a pure material.
-28-
2~1466~
iv~ ~ ~
The purest sampie, the product of Example 5, was found
to demonstrate the following cation/site balance as synthesized:
(~a+K)/(2Ti+~l) = .97
These materials are easily exchangeable with cationic
species such as ammonium, with little or no change in XRD
spectrum as is obvious from the following table which shows
ammonium exchange. Magnesium and calcium data will be later
presented.
- 29 -
',~ .
2014666
TABLE
COMPOSITION AND XRD PEAK POSITIONS OF AS-SYNTHESIZED AND
HIGHLY AMMONIUM EXCHANGED ETS-10 AND THE PRODUCTS OF
EXAMPLES 5 AND 7
ETS-10
ELEMENTAL COMPOSITION (WT%) XRD PEAK POSITION (A)
AS-SYNTHESIZED NH4 EXCHANGED AS SYNTHESIZED NH4 EXCHANGED
d-spacing A I/Io d-spacing I/Io
SiO261.4070.12 14.7 W-M 14.75 W-M
TiO222.7227.12 7.20 W-M 7.20 W-M
Al2O3 0.28 0.26 4.41 W-M 4.415 VS
Na2O13.751.58 3.60 VS 3.60 W-M
K2O3.30.07 3.28 W-M 3.28 W-M
(Na+K)/2Ti= 0.89 (as synthesized)
(Na+K)/2Ti= .08 (after exchange)
EXAMPLE 5
ELEMENTAL COMPOSITION (WT~) XRD PEAK POSITION (A)
AS-SYNTHESIZED NH4 EXCHANGED AS SYNTHESIZED NH4 EXCHANGED
d-spacing A I/Io d-spacing I/Io
SiO258.74 67.77 14.97 W-M 14.91 W-M
TiO218.48 21.83 --- --- 7.24 W-M
Al2O33.89 6.71 4.45 W-M 4.43 W-M
Na2O12.51 2.80 3.65 VS 3.62 VS
K2O 5.56 1.24 3.31 M-S 3.30 M-S
(Na+K)/(2Ti+Al) = 0.97 (as synthesized)
(Na+K)/(2Ti+Al) = 0.17 (after exchange)
EXAMPLE 7
ELEMENTAL COMPOSITION (WT%) XRD PEAK POSITION (A)
AS-SYNTHESIZED NH4 EXCHANGED AS SYNTHESIZED NH4 EXCHANGED
d-spacing A I/Io d-spacing I/Io
SiO254.52 61.77 15.25 W-M 15.30 W-M
TiO217.23 19.72 --- --- ---
Al2O39.70 11.30 4.45 W-M 4.40 W-M
Na2O14.93 5.25 3.68 VS 3.68 VS
K2O 4.18 1.78 3.33 M-S 3.33 M-S
(Na+k)/(2Ti+Al) = 0.92 (as synthesized)
(Na+K)/(2Ti+Al) = 0.29 (after exchange)
-30-
X
2ol~666
EXAMP~E lO
The product of Example 5 was contacted with a lO~ by
weight solution of magnesium chloride for l/2 hour at 100~C.
After washing with deionized water and calcining at 500~C for
1 hour, and re-equilibrated in air, the crystalline product had
the following d-spacings:
o
d-spacing~ (A) I/Io
14.97 23
7.20 (no longer observed)
5.01 6
4.43 10
3.78 6
3.63 lO0
3.31 28
2.540 26
2.479 lO
The elemental composition was as follows ~wt.~):
SiO2 60.76
TiO2 18.96
A12n3 5.60
Na20 5.~2
K20 3.62
MgO 5 47
2~g+Na+K/(2Ti+Al) = 0.~2
- ..... . _ .
.
2014666
.
EXAMPLE 11
The product of Example 7 was contacted with a 10~ by
weight solution of magnesium chloride for 1/2 hour at 100~C.
After washing with deionized water and calcining at 500~ for 1
hour, and re-equilibrated in air, the crystalline product had
the following d-spacings:
d-spacings (A) I/Io
15.06 16
7.20 (no longer observed)
5.08 26
4.43 8
3.66 100
3.32 30
2.564 24
2.535 20
2.493 11 '
The elemental composition was as follows (wt.~):
SiO2 56.20
TiO2 17.30
A12~3 9.85
Na20 9.32
K20 3.09
MgO 4.64
2Mg+Na+K/(2Ti+Al) = 0.95
.: ~ ",~''
20146~
.,
EXAMPLE 12
The product of example 5 was contacted with a 5% by
weight solution of calcium chloride dihydrate for 1/2 hour at
100~C a total of 2 times. After washing with deionized water
and calcining at 200~C for 1 hour, and re-equilibrated in air,
the crystalline product had the following d-spacings:
o
d-~pacinqs (A) I/I
14.9 W-M
7.2 (not observed)
4.42
3.615 VS
3.290 M-S
The elemental composition was as follows (wt.~):
SiO2 59 .93
TiO2 19.23
A12~3 5.69
Na20 1.61
g2~ 2.76
CaO 11.31
2Ca+Na+~/(2Ti+Al) = 0.92
EXAMPLE 13
While the aluminum coordination may be inferred to be
tetrahedral from the cation balance of the previous examples,
~1 ~IMR may be employed to more definitively establish
'~L
2014666
-
whether Al is tetrahedral or octahedral and whether it is
"framework" aluminum as would be expected if it were
integrated into a molecular sieve. The 27 AI MAS NMR
spectrum of a sample of ETAS-10 containing approximately
7.2 wt. % A1203 was obtained and shows a peak at 58 ppm
which is indicative of tetrahedral framework aluminum.
No octahedral aluminum was observed, the small peak at -6
ppm being interpreted as a spinning side band.
This example establishes that essentially all
aluminum incorporated into the gross reaction product of
ETAS-10 reaction mixtures forms as tetrahedral, framework
type sites. This example does not eliminate the
possibility of mixed phases, including the possibility of
an alumino-silicate zeolite co-forming with ETS-10 in
ETAS-10 reaction mixtures.
EXAMPLE 14
The ETAS-10 sample of the previous example was
subjected to standard SEM/EDS analysis. The morphology
of the dominant crystal species (established from XRD to
be ETAS-10) was found to be platy masses, notably
different than the nearly cubic crystals characteristic
for ETS-10. Spot elemental analysis of the sample
indicated that aluminum was uniformly associated with
crystals bearing both high titanium and high silicon
levels. No masses or crystals containing significant
aluminum were observed which did not also contain
substantial titanium observed, i.e. no alumino-silicate
phases were observed.
- 34 -
.,
2014666
This example establishes that aluminum incorporated
into the gross reaction product of ETAS-10 reaction
mixtures forms as crystalline titanium-aluminum-silicates
and not as a mixture of crystalline titanium-silicates
and classical alumino-silicate zeolites.
CONCLUSIONS FROM EXAMPLES 9-14
Examples 9-14 established that aluminum is
incorporated as a tetrahedral framework atom in a
crystalline titanium-aluminum-silicate phase during the
crystallization of ETAS-10 reaction mixtures.
EXAMPLE 15
The gross products of examples 1, 5 and 8 were
ammonium exchanged, activated under vacuum at 350~C and
exposed to xenon at 530 torr pressure. The xenon treated
samples were then subjected to 129Xe NMR. Some crystal-
linity was lost. The spectra of the ETS-10 of example 1
shows a clean spectrum with a peak at 119.3 ppm.
Aluminum incorporated dramatically upshifts this peak
position. The product of example 5 shows a clear single
peak at 137.6 ppm, establishing that the ETAS-10 of
example 5 is a single crystalline phase, easily differen-
tiated from the ETS-10 of example 1 by a standard
analytical technique. Substantially increasing the
aluminum level in example 8 only raises the primary peak
an additional 2 ppm (to 139.8), clearly demonstrating
that the characteristic peak locations for ETAS-10 cover
a relatively narrow region, far removed from that
characteristic for ETS-10, irrespective of incorporated
aluminum level under the test conditions stated.
-35-
201~666
EXAMPLE 16
The 29Si MAS NMR spectrum of ETS-10 and the ETAS-10
of example 10 were obtained. The ETS-10 spectrum
indicates three distinct silicate environments as
manifested by peaks at -104, -96 and -94 ppm. The ETAS-
10 spectrum demonstrates these three environments plus at
least two new heavily populated environments as
manifested by additional significant peaks at -92 and -90
ppm. Such new environments would be expected if silica
and alumina were integrated into the same crystal.
Having established in the previous example that ETAS-10
is a single phase, it is evident that aluminum
incorporation impacts the silica sites of the structure
and that an additional standard analytical method may be
employed to readily differentiate ETS-10 from ETAS-10.
CONCLUSIONS FROM EXAMPLES 15 & 16
These two examples demonstrate that the ETAS-10
samples of the previous examples represent a single
distinct phase which can be readily differentiated from
ETS-10 by a variety of standard analytical techniques.
EXAMPLE 17
The ETAS-10 sample of example 13 was activated under
vacuum at 200~C and exposed to 1,3,5-trimethylbenzene.
Under these conditions, an adsorptive capacity of 6.4
wt.% was observed for this as synthesized, mixed Na'/~
material.
- 36 -
~i i .
2014666
As synthesized, mixed Na+/K~ ETS-10 has been observed to
be essentially non-adsorptive towards 1,3,5-
trimethylbenzene, the molecule being slightly larger than
the as synthesized ETS-10 pore opening.
This example demonstrates that the pore opening of
ETAS-10 is somewhat larger than ETS-10. This is
consistent with the lattice expansion examples 1-8 as
aluminum is incorporated into the reaction mixture.
EXAMPLE 18
The products of examples 1 and 5 were air
equilibrated and dehydrated in a TGA apparatus at
10~/min. ETS-10 is a weak, type I moderate adsorbent
towards small polar molecules and began rapidly losing
water at a temperature slightly above 100~C. Under
equivalent conditions, the ETAS-10 of example 5 lost the
preponderance of absorbed water only after a pronounced
drop-off point at approximately 250~C. This demonstrates
that the incorporation of even 3.9 wt.% Al2O3 profoundly
alters the internal electrostatic field of the material,
binding small polar molecules such water much more
tightly.
CONCLUSIONS FROM EXAMPLES 17 AND 18
These two examples demonstrate that ETAS-10 has a
somewhat larger pore an grossly different internal
electrostatic environment that ETS-10. These two points
are completely consistent with the lattice expansion
observed in examples 1-8 and the distinct xenon shift
(probably indicative of much stronger xenon/site
interactions) of example 14 and the new silica
environments of example 16.
E~
201~6~
EX~MPLES 19-23
These examples demonstrate that the preparation of
ETAS-10 is not as simple as the addition of an aluminum source
to a "standard~ ETS-10 synthesis mixture followed by
crystallization. Specific pR levels, depending upon desired ' i
degree of aluminum incorporation, must be in place while the
reactant gel is formed. These examples further demonstrate
that if aluminum addition is made at the wrong gel pH,
formation of ETAS-10 by rebalancing pH to the level appropriate
for ETAS-10 formation is difficult at best.
FXAMP~E 1~
A 200 9 sample of the ETS-10 ael of example 1 was
segregated from the larger lot and to this sample was added
20.8 g of reagent grade AlC13-6~20 such that the ratio of
Al/Ti was approximately 1.0, as in examples 7 and 8. The
sample was thoroughly blended and the "pH" of the gel, after a
10 min. equilibration period, was found to be approximately
7.8, well below the region associated with ETS-10 lor ETAS-10
formation. Three small samples (8-ln g each) were withdrawn
from this now aluminum bearing lot and crystallized under the
conditions of the previous example for 1, 3 and 7 days,
respectively. After washing and drying as above, X~D powder
patterns revealed the reaction products to be essentially
amorphous (approximately 10~ crystallinity) with the small
amount of crystallized product devoid of ETS-10, ETAS-10 or
related phases in all cases.
~,~
.,- ,. ~
201~66~
EXAMPLE 20
A 200 g sample of the ETS-10 gel of example 1 was
segregated from the larger lot and to this sample was
added 6.7 g of Al2O3 ~ 6H2O such that the ratio of Al/Ti
was approximately 1.0, as in examples 7 and 8. The
sample was thoroughly blended and the "pH" of the gel,
after a 10 min. equilibration period, was found to be
approximately 10.1, essentially unchanged from the raw
ETS-10 gel. Three small samples (8-10 g each) were
withdrawn from this now aluminum bearing lot and
crystallized under the conditions of the previous example
for 1, 3 and 7 days, respectively. After washing and
drying as above, XRD powder patterns revealed the
reaction products to be highly crystalline ETS-4,
essentially devoid of ETS-10, ETAS-10 or related phases.
EXAMPLE 21
A 200 g sample of the ETS-10 gel of example 1 was
segregated from the larger lot and to this sample was
added 7.1 g of NaAlO2 such that the ratio of Al/Ti was
approximately 1.0, as in examples 7 and 8. The sample
was thoroughly blended and the "pH" of the gel, after a
10 min. equilibration period, was found to be
approximately 10.7, an apparently nearly ideal level for
ETAS-10 formation at this aluminum content. Three small
samples (8-10 g each) were withdrawn from this now
aluminum bearing lot and crystallized under the
conditions of the previous example for 1, 3 and 7 days,
respectively. After washing and drying as above, XRD
powder patterns revealed the reaction products to be
highly crystalline ETS-4, essentially devoid of ETS-10,
ETAS-10 or related phases.
-39-
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2014666
.
EXAMPLE 22
TO the remainder of the relatively low (for ETAS-10
formation) alkalinity mixture of_example 20 was added 3.5 g of
NaOH with the resultant mixture thoroughly blended by over-head
stirrer, The resultant "pH" was raised to approximately
10.75, A small portion of the sample (8-lq g) was crystallized
for 24 hours at 200~C as above. A crystalline product was
obtained which was predominantly ETS-4 (estimated to be
approximately 80~) with no trace of any ETS-10 or ETAS-10-like
phase observed.
EXAMPLE 23
To the remainder of the remainder of the nearly ideal
(for ETAS-10 formation) alkalinity mixture of example 19 was
added an additional 1.0 g of ~aOH with the resultant mixture
thoroughly blended by over-head stirrer. The resultant "pH"
was raised to approximately 10.80. A small portion of the
sample (8-10 g) was crystallized for 24 hours at 200~C as
above. A crystalline product was obtained which was
predominantly ETS-4 (estimated to be approximately 80~) with no
trace of any ETS-10 or ETAS-10-like phase observed.
CONCLUSIO~S
ETAS-10 is a new wide pored titanium-aluminum-silicate
molecular sieve constructed from di-charged octahedral
titanium, mono-cnarged tetrahedral aluminum and neutral
tetrahedral silica units. NO such sieve containing both
charged octahedral and charged tetrahedral sites is noted in
~he prior art.
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While structurally related to the titanium-silicate
molecular sieve ETS-10, incorporation of aluminum into
the framework structure systematically expands the
lattice planes and pore openings. The incorporated
aluminum generates strongly polarized sites which, in
concert with the di-charged titanium sites, generate a
unique intercrystalline environment.
The synthesis of ETAS-10 is similar to that of ETS-
10 with the exception that a soluble aluminum source is
added to the synthesis mixture and the "pH" must be
adjusted upward at the time of gel formation depending
upon aluminum level. It also appears that this elevated
alkalinity must be present at or shortly after gel
formation. ETS-10 contains incidental amounts of
aluminum typically 0.5 wt.~ as Al203 on a volatile free
basis, as a consequence of less than perfect reactant
purity, especially contamination in commercial sodium
silicates. ETAS-10 contains substantial amounts of
aluminum (about 0.5 to 10 wt.~ or more as Al203) as a
consequence of the intentional incorporation of aluminum
into the sieve by the addition of an aluminum source to
the reaction mixture.
ETAS-10 represents a new composition of matter which
can be differentiated from ETS-10 by a variety of
standard analytical techniques.
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201~G66
~1 , ,
~,;
~LOSSARY OF TERMS ~
;~
DEFINITION " PROCEDURES AND REACTANTS EMPLOYED
- ~ Brand Sodium Silicate is a commercial solution
obtained from PQ Corporation. Typical lot analysis
would .nclude approximately 29 wt.% Si02 and 9 wt.
caustic as Na20, the balance being water.
- SDS (sodium di-silicate) is a commercially used sodium
silicate solution in Engelhard FCC operations and was
obtained internally. Typically lot analysis would
include approximately 27 wt.% Si02 and 14 wt.%
caustic as Na20, the balance being water.
- Potassium fluoride (KF~ was obtained on an anhydrous
- basis from Pfaltz and Bauer, Inc. Solubility of
fluorides in the silicate solutions employed is such
that they are only partially dissolved upon mixing,
the balance appearing suspended in the silicate
mixtures. , -
: :
- Caustic (NaOH~ was obtained as an essentially
anhydrous material from Fisher Scientific.
~:
- Titanous Chloride solution (TiC13 ? was obtained from
Fisher Scientific as 20 wt.% TiC13 in 20 wt.% HCl,
the balance being water yielding a net molality of
1.25 - 1.30 TiC13.
- Titanium tetrachloride (TiC14) was obtained as a +99
wt.% liquid from Alfa-Ventron.
- Aluminum trichloride as the hexa-aquated salt
(AlC13'6~20) was obtained from Fisher Scientific. ,
The aluminum trichloride is completely dissolved in
the titanous chloride solution before the mixed metal
solution is blended into alkaline silicate mixtures.
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, i~ .
2014666
.
- Sodium aluminate (NaAlO2) was obtained on an
essentially anhydrous basis from Pfaltz and Bauer, Inc.
Where this reactant is employed as the aluminum source,
sodium aluminate is added as a solid to freshly prepared
titanium silicate gels and blended until it apparently
dissolves.
- Sodium Chloride (NaCl) was obtained as an
essentially anhydrous salt from Fisher Scientific.
Sodium chloride was added to mixtures of low aluminum
content to increase the ion content to a level
approaching that of the higher aluminum content mixtures.
- Calcined seed crystals are obtained by calcining a
standard pilot plant run of approximately 80~ ETS-10 and
15~ ETS-4 to a temperature greater than 300~C but less
than 500~C such that the ETS-4 decomposes while ETS-10
remains in tact. Seeds are not essential to ETAS-10
formation, but appear to shorten reaction times and
broaden the range of acceptable gel compositions.
- Thoroughly blended refers to gels which have been
stirred by overhead stirrers to the point where they
visually appear homogeneous. All blending is done at
ambient temperature although acid base reactions and base
dissolution may temporarily elevate the temperature of
the gel.
- All products of the examples are vacuum filtered,
washed with an excess of deionized water (at least 10
cc/g) and dried at 200~C for at least 30 minutes prior to
any further treatment or testing.
- Air-equilibration is carried out by exposure of
dried samples to ambient air for a period of at least one
hour.
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_
- SEM/EDS is scanning electron microscopy and energy
dispersive spectroscopy.
- Elemental analyses are presented on a volatile free
basis as determined by x-ray fluorescence. The x-ray
fluorescence sample preparation technique used involves
exposure to elevated temperature - typically 1100~C.
Thus, the samples presented as ammonium exchanged are in
reality the hydrogen form since the said exposure at
elevated temperatures converts the samples to some
hydrogen form.
- 27Al N.M.R Spectra 27Al N.M.R Spectra MAS NMR
spectroscopy is a technique used to characterize the
aluminum species in alumino-silicates and zeolites. All
spectra were obtained from Spectral Data Services, Inc.,
Champaign, IL. 27Al Spectra were run by standard methods
exposing the sample to a magnetic field of 8.45 tesla and
spinning the sample at a rate of 8 kHz at the so-called
magic angle, which reduces shielding anisotropy and
dipolar interaction. Spectra were an average of 3000 to
8000 scans to increase resolution and signal-to-noise
with a 0.3 sec recycle and summed. All samples were air-
equilibrated (i.e. contained absorbed water) before
running spectra. Such equilibrated both makes a
reproducible state of hydration and enhances the
observation of 27Al MAS NMR species by increasing the
techniques sensitivity.
- l9Si N.M.R. Spectra 29Si MAS NMR Spectroscopy is a
technique used to characterize the silicon species in
alumino-silicates and zeolites. All spectra were
obtained from Spectral Data Services, Inc., Champaign,
IL. 29Si spectra were run by standard methods exposing
the sample to a magnetic field of 6.3 tesla and spinning
the sample at a rate of 4kHz at the so called magic
angle, which reduces shielding anisotropy and dipolar
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2014666
interaction. Spectra were an average of 200 to 1500
scans to increase resolution and single-to-noise with a
80 to 120 sec recycle and summed. All samples were air-
equilibrated (i.e. contained adsorbed water) before
running spectra. Such equilibrated samples contain 15-20
wt.9o- water. This equilibration both makes a reproducible
state of hydration and enhances the observation of 23Si
MAS NMR species by increasing the techniques sensitivity.
- Discharged Titanium - Titanium centers generate a
charge of -2 when in octahedral coordination with oxygen.
The charge results from 6 shared oxygen atoms impacting a
charge of -12/2 = -6. Ti (IV) imparts a charge of +4
such that the coordinated titanium center bears a net
charge of -2.
- Monocharged aluminum - Aluminum centers generate a
charge of -1 when in tetrahedral coordination with
oxygen. The charge results from 4 shared oxygen atoms
imparting a charge of -8/2 = -4. Al (III) imparts a
charge of +3 such that the coordinated aluminum center
bears a net charge of -1.
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