Molecular sieve abstract
Molecular sieve compositions having three-dimensional microporous
framework structures of BeO.sub.2 AlO.sub.2 and PO.sub.2 tetrahedral
oxide units are disclosed. These molecular sieves have an empirical
chemical composition on an anhydrous basis expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Be.sub.x Al.sub.y P.sub.z)O.sub.2 ; and "x", "y"
and "z" represent the mole fractions of beryllium, aluminum
and phosphorus, respectively, present as tetrahedral oxides. Their
use as adsorbents, catalysts, etc. is also disclosed.
Molecular sieve claims
We claim:
1. Crystalline molecular sieves having three-dimensional microporous
framework structures of BeO.sub.2 AlO.sub.2 and PO.sub.2 tetrahedral
units having an empirical chemical composition on an anhydrous basis
expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Be.sub.x Al.sub.y P.sub.z)O.sub.2 and has a value of zero to about
0.3; and "x", "y" and "z" represent
the mole fractions of beryllium, aluminum and phosphorus, respectively,
present as tetrahedral oxides, said mole fractions being such that
they are within the hexagonal compositional area defined by points
A, B, C, D, E and F of FIG. 1 said crystalline molecular sieves
having a characteristic X-ray powder diffraction pattern which contains
at least the d-spacings set forth in one of the following Tables
A to H and J to V:
2. Crystalline molecular sieves according to claim 1 wherein the
mole fractions or beryllium, aluminum and phosphorus present as
tetrahedral oxides are within the tetragonal compositional area
defined by points a, b, c and d of FIG. 2.
3. Crystalline molecular sieves according to claim 2 wherein the
mole fractions of beryllium, aluminum and phosphorus present as
tetrahedral oxides are within the triangular compositional area
defined by points e, f and g of FIG. 2.
4. Crystalline molecular sieves according to claim 1 wherein "m"
is not greater than about 0.15.
5. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table A given in claim 1.
6. The crystalline molecular sieves of claim 5 wherein the X-ray
powder diffraction pattern set forth in Table A contains at least
the d-spacings set forth in one of the following Tables AA and AB:
7. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table B given in claim 1.
8. The crystalline molecular sieves of claim 7 wherein the X-ray
powder diffraction pattern set forth in Table B contains at least
the d-spacings set forth in one of the following Tables BA and BB:
9. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table C given in claim 1.
10. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table D given in claim 1.
11. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table E given in claim 1.
12. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table F given in claim 1.
13. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table G given in claim 1.
14. The crystalline molecular sieves of claim 13 wherein the X-ray
powder diffraction pattern set forth in Table G contains at least
the d-spacings set forth in one of the following Tables GA and GB:
15. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table H given in claim 1.
16. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table J given in claim 1.
17. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table K given in claim 1.
18. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table L given in claim 1.
19. The crystalline molecular sieves of claim 18 wherein the X-ray
powder diffraction pattern set forth in Table L contains at least
the d-spacings set forth in one of the following Tables LA, LB and
LC:
20. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table M given in claim 1.
21. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table N given in claim 1.
22. The crystalline molecular sieves of claim 21 wherein the x-ray
powder diffraction pattern set forth in Table N contains at least
the d-spacings set forth in the following Table NA:
23. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table 0 given in claim 1.
24. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table P given in claim 1.
25. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table Q given in claim 1.
26. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table R given in claim 1.
27. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table S given in claim 1.
28. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table T given in claim 1.
29. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table U given in claim 1.
30. The crystalline molecular sieves of claim 1 or 2 having a characteristic
X-ray powder diffraction pattern which contains at least the d-spacings
set forth in Table V given in claim 1.
31. Process for preparing crystalline molecular sieves having three-dimensional
microporous framework structures of BeO.sub.2 Al.sub.2 and PO.sub.2
tetrahedral units having an empirical chemical composition on an
anhydrous basis expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Be.sub.x Al.sub.y P.sub.z)O.sub.2 and has a value of zero to about
0.3; and "x", "y" and "z" represent
the mole fractions of beryllium, aluminum and phosphorus, respectively,
present as tetrahedral oxides, said mole fractions being such that
they are within the hexagonal compositional area defined by points
A, B, C, D, E and F of FIG. 1 said crystalline molecular sieves
having a characteristic X-ray powder diffraction pattern which contains
at least the d-spacings set forth in one of the following Tables
A to H and J to V:
the process comprising providing a reaction mixture composition
at an effective temperature and for an effective time sufficient
to produce the molecular sieves, said reaction mixture composition
being expressed in terms of molar oxide ratios as follows:
wherein "R" is an organic templating agent; "a"
is the amount of "R" and is an effective amount greater
than zero to about 6; "b" has a value of from zero to
about 500; and "u", "v" and "w" represent
the mole fractions, respectively, of beryllium, aluminum and phosphorus
in the (Be.sub.u Al.sub.v P.sub.w)O.sub.2 constituent, and each
has a value of at least 0.01.
32. Process according to claim 31 wherein "x", "y"
and "z" are within the pentagonal compositional area defined
by points G, H, I, J and K of FIG. 3.
33. Process according to claim 32 wherein "x", "y"
and "z" are within the pentagonal compositional area defined
by points g, h, i, j and k of FIG. 3.
34. Process according to claim 31 wherein "a" is not
greater than about 1.5.
35. Process according to claim 31 wherein "b" has a value
of from 2 to 50.
36. Process according to claim 31 wherein the source of phosphorus
in the reaction mixture is orthophosphoric acid.
37. Process according to claim 31 wherein the source of phosphorus
in the reaction mixture is orthophosphoric acid and the source of
aluminum is at least one compound selected from the group consisting
of pseudo-boehmite and aluminum alkoxide.
38. Process according to claim 37 wherein the aluminum alkoxide
is aluminum isopropoxide.
39. Process according to claim 31 wherein the source of beryllium
is selected from the group consisting of oxides, hydroxides, alkoxides,
chlorides, bromides, iodides, sulfates, nitrates, carboxylates and
mixtures thereof.
40. Process according to claim 31 or claim 32 wherein the organic
templating agent is a quaternary ammonium or quaternary phosphonium
compound having the formula:
wherein X is nitrogen or phosphorus and each R is an alkyl or aryl
group containing from 1 to 8 carbon atoms.
41. Process according to claim 31 wherein the organic templating
agent is an amine.
42. Process according to claim 31 wherein the templating agent
is selected from the group consisting of tetrapropylammonium ion;
tetraethylammonium ion; tripropylamine; triethylamine; triethanolamine;
piperidine; cyclohexylamine; 2-methyl pyridine; N,N-dimethylbenzylamine;
N,N-dimethylethanolamine; choline; N,N-dimethylpiperazine; 14-diaziabicyclo-(222)
octane; N-methyldiethanolamine; N-methylethanolamine; N-methylpiperidine;
3-methylpiperidine; N-methylcyclohexylamine; 3-methylpyridine; 4-methylpyridine;
quinuclidine; N,N'-dimethyl-14-diazabicyclo (222) octane ion;
tetramethylammonium ion; tetrabutylammonium ion; tetrapentylammonium
ion; di-n-butylamine; neopentylamine; d-n-pentylamine; isopropylamine;
t-butylamine; ethylenediamine; pyrrolidone; 2-imidazolidone; di-n-propylamine;
and a polymeric quaternary ammonium salt [(C.sub.14 H.sub.32 N.sub.2)(OH).sub.2
].sub.x wherein x has a value of at least 2.
43. Molecular sieves prepared by calcining, at a temperature sufficiently
high to remove at least some of any organic templating agent present
in the intracrystalline pore system, the crystalline molecular sieves
having three-dimensional microporous framework structures of BeO.sub.2
AlO.sub.2 and PO.sub.2 tetrahedral units having an empirical chemical
composition on an anhydrous basis expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Be.sub.x Al.sub.y P.sub.z)O.sub.2 and has a value of zero to about
0.3; and "x", "y" and "z" represent
the mole fractions of beryllium, aluminum and phosphorus, respectively,
present as tetrahedral oxides, said mole fractions being such that
they are within the hexagonal compositional area defined by points
A, B, C, D, E and F of FIG. 1 said crystalline molecular sieves
having a characteristic X-ray powder diffraction pattern which contains
at least the d-spacings set forth in one of the following Tables
A to H and J to V:
44. Crystalline molecular sieves having three-dimensional microporous
framework structures of BeO.sub.2 AlO.sub.2 and PO.sub.2 tetrahedral
units having an empirical chemical composition on an anhydrous basis
expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Be.sub.x Al.sub.y P.sub.z)O.sub.2 and has a value of zero to about
0.3; and "x", "y" and "z" represent
the mole fractions of beryllium, aluminum and phosphorus, respectively,
present as tetrahedral oxides, said mole fractions being such that
they are within the hexagonal compositional area defined by points
A, B, C, D, E and F of FIG. 1.
45. Crystalline molecular sieves according to claim 44 wherein
the mole fractions of beryllium, aluminum and phosphorus present
as tetrahedral oxides are within the tetragonal compositional area
defined by points a, b, c and d of FIG. 2.
46. Crystalline molecular sieves according to claim 45 wherein
the mole fractions of beryllium, aluminum and phosphorus present
as tetrahedral oxides are within the triangular compositional area
defined by points e, f and g of FIG. 2.
47. The crystalline molecular sieves according to claim 44 wherein
"m" is not greater than about 0.15.
48. Process for preparing crystalline molecular sieves having three-dimensional
microporous framework structures of BeO.sub.2 AlO.sub.2 and PO.sub.2
tetrahedral units having an empirical chemical composition on an
anhydrous basis expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Be.sub.x Al.sub.y P.sub.z)O.sub.2 and has a value of zero to about
0.3; and "x", "y" and "z" represent
the mole fractions of beryllium, aluminum and phosphorus, respectively,
present as tetrahedral oxides, said mole fractions being such that
they are within the hexagonal compositional area defined by points
A, B C, D, and E and F of FIG. 1 the process comprising providing
a reaction mixture composition at an effective temperature and for
an effective time sufficient to produce the molecular sieves, said
reaction mixture composition being expressed in terms of molar oxide
radios as follows:
wherein "R" is an organic templating agent; "a"
is the amount of "R" and is an effective amount greater
than zero to about 6; "b" has a value of from zero to
about 500; and "u". "v" and "w" represent
the mole fractions, respectively, of beryllium, aluminum and phosphorus
in the (Be.sub.u Al.sub.v P.sub.w)O.sub.2 constituent, and each
has a value of at least 0.01.
49. Process according to claim 48 wherein "x", "y"
and "z" are within the pentagonal compositional area defined
by points G, H, I, J and K of FIG. 3.
50. Process according to claim 49 wherein "x", "y"
and "x" are within the pentagonal compositional area defined
by points g, h, i, j and k of FIG. 3.
51. Process according to claim 48 wherein "a" is not
greater than about 1.5.
52. Process according to claim 48 wherein "b" has a value
of from 2 to 50.
53. Process according to claim 48 wherein the source of phosphorus
in the reaction mixture is orthophosphoric acid.
54. Process according to claim 48 wherein the source of phosphorus
in the reaction mixture is orthophosphoric acid and the source of
aluminum is at least one compound selected from the group consisting
of pseudo-boehmite and aluminum alkoxide.
55. Process according to claim 54 wherein the aluminum alkoxide
is aluminum isopropoxide.
56. Process according to claim 48 wherein the source of beryllium
is selected from the group consisting of oxides, hydroxides, alkoxides,
chlorides, bromides, iodides, sulfates, nitrates, carboxylates and
mixtures thereof.
57. Process according to claim 48 wherein the organic templating
agent is a quaternary ammonium or quaternary phosphonium compound
having the formula:
wherein X is nitrogen or phosphorus and each R is an alkyl or aryl
group containing from 1 to 8 carbon atoms.
58. Process according to claim 48 wherein the organic templating
agent is an amine.
59. Process according to claim 48 wherein the templating agent
is selected from the group consisting of tetrapropylammonium ion;
tetraethylammonium ion; tripropylamine; triethylamine; triethanolamine;
piperidine; cyclohexylamine; 2-methyl pyridine; N,N-dimethylbenzylamine;
N,N-dimethylethanolamine; choline; N,N-dimethylpiperazine; 14-diaziabicyclo-(222)
octane; N-methyldiethanolamine; N-methylethanolamine; N-methylpiperidine;
3-methylpiperidine; N-methylcyclohexylamine; 3-methylpyridine; 4-methylpyridine;
quinuclidine; N,N,dimethyl-14-diazabicyclo (222) octane ion;
tetramethylammonium ion; tetrabutylammonium ion; tetrapentylammonium
ion; di-n-butylamine; neopentylamine; di-n-pentylamine; isopropylamine;
t-butylamine; ethylenediamine; pyrrolidine; 2-imidazolidone; di-n-propylamine;
and a polymeric quaternary ammonium salt [(C.sub.14 H.sub.32 N.sub.2)(OH).sub.2
].sub.x wherein x has a value of at least 2.
60. Molecular sieves prepared by calcining, at a temperature sufficiently
high to remove at least some of any organic templating agent present
in the intracrystalline pore system, the crystalline molecular sieves
having three-dimensional microporous framework structures of BeO.sub.2
AlO.sub.2 and PO.sub.2 tetrahedral units having an empirical chemical
composition on an anhydrous basis expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Be.sub.x Al.sub.y P.sub.z)O.sub.2 and has a value of zero to about
0.3; and "x", "y" and "z" represent
the mole fractions of beryllium, aluminum and phosphorous, respectively,
present as tetrahedral oxides, said mole fractions being such that
they are within the hexagonal compositional area defined by points
A, B, C, D and E and F of FIG. 1
Molecular sieve description
FIELD OF THE INVENTION
The instant invention relates to a novel class of crystalline microporous
molecular sieves and to the method of their preparation. The invention
relates to novel beryllium-aluminum-phosphorus-oxide molecular sieves
containing framework tetrahedral oxide units of beryllium, aluminum
and phosphorus. These compositions may be prepared hydrothermally
from gels containing reactive compounds of beryllium, aluminum and
phosphorus capable of forming framework tetrahedral oxides, and
preferably at least one organic templating agent which functions
in part to determine the course of the crystallization mechanism
and the structure of the crystalline product.
BACKGROUND OF THE INVENTION
Molecular sieves of the crystalline alumino-silicate zeolite type
are well known in the art and now comprise over 150 species of both
naturally occurring and synthetic compositions. In general the crystalline
zeolites are formed from corner-sharing AlO.sub.2 and SiO.sub.2
tetrahedra and are characterized by having pore openings of uniform
dimensions, having a significant ion-exchange capacity and being
capable of reversibly desorbing an adsorbed phase which is dispersed
throughout the internal voids of the crystal without displacing
any atoms which make up the permanent crystal structure.
Other crystalline microporous compositions which are not zeolitic,
i.e. do not contain AlO.sub.2 tetrahedra as essential framework
constituents, but which exhibit the ion-exchange and/or adsorption
characteristics of the zeolites are also known. Metal organosilicates
which are said to possess ion-exchange properties, have uniform
pores and are capable of reversibly adsorbing molecules having molecular
diameters of about 6 .ANG. or less, are reported in U.S. Pat. No.
3941871 issued Mar. 2 1976 to Dwyer et al. A pure silica polymorph,
silicalite, having molecular sieving properties and a neutral framework
containing neither cations nor cation sites is disclosed in U.S.
Pat. No. 4061724 issued Dec. 6 1977 to R. W. Grose et al.
A recently reported class of microporous compositions and the first
framework oxide molecular sieves synthesized without silica, are
the crystalline aluminophosphate compositions disclosed in U.S.
Pat. No. 4310440 issued Jan. 12 1982 to Wilson et al. These materials
are formed from AlO.sub.2 and PO.sub.2 tetrahedra and have electrovalently
neutral frameworks as in the case of silica polymorphs. Unlike the
silica molecular sieve, silicalite, which is hydrophobic due to
the absence of extra-structural cations, the aluminophosphate molecular
sieves are moderately hydrophilic, apparently due to the difference
in electronegativity between aluminum and phosphorus. Their intracrystalline
pore volumes and pore diameters are comparable to those known for
zeolites and silica molecular sieves.
In U.S. Pat. Nc. 4440871 there is described a novel class of
silicon-substituted aluminophosphates which are both microporous
and crystalline. The materials have a three dimensional crystal
framework of PO.sub.2.sup.+, AlO.sub.2.sup.- and SiO.sub.2 tetrahedral
units and, exclusive of any alkali metal or calcium which may optionally
be present, an as-synthesized empirical chemical composition on
an anhydrous basis of:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the moles of "R" present per mole of (Si.sub.x
Al.sub.y P.sub.z)O.sub.2 and has a value of from zero to 0.3 the
maximum value in each case depending upon the molecular dimensions
of the templating agent and the available void volume of the pore
system of the particular silicoaluminophosphate species involved;
and "x", "y", and "z" represent the
mole fractions of silicon, aluminum and phosphorus, respectively,
present as tetrahedral oxides. The minimum value for each of "x",
"y", and "z" is 0.01 and preferably 0.02. The
maximum value for "x" is 0.98; for "y" is 0.60;
and for "z" is 0.52. These silicoaluminophosphates exhibit
several physical and chemical properties which are characteristic
of aluminosilicate zeolites and aluminophosphates.
In U.S. Pat. No. 4500651 there is described a novel class of
titanium-containing molecular sieves whose chemical composition
in the as-synthesized and anhydrous form is represented by the unit
empirical formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the moles of "R" present per mole of (Ti.sub.x
Al.sub.y P.sub.z)O.sub.2 and has a value of between zero and about
5.0; and "x", "y" and "z" represent
the mole fractions of titanium, aluminum and phosphorus, respectively,
present as tetrahedral oxides.
In U.S. Pat. No. 4567029 there is described a novel class of
crystalline metal aluminophosphates having three-dimensional microporous
framework structures of MO.sub.2 AlO.sub.2 and PO.sub.2 tetrahedral
units and having an empirical chemical composition on an anhydrous
basis expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the moles of "R" present per mole of (M.sub.x
Al.sub.y P.sub.z)O.sub.2 and has a value of from zero to 0.3; "M"
represents at least one metal of the group magnesium, manganese,
zinc and cobalt; "x", "y", and "z"
represent the mole fractions of the metal "M", aluminum
and phosphorus, respectively, present as tetrahedral oxides.
In U.S. Pat. No. 4544143 there is described a novel class of
crystalline ferroaluminophosphates having a three-dimensional microporous
framework structure of FeO.sub.2 AlO.sub.2 and PO.sub.2 tetrahedral
units and having an empirical chemical composition on an anhydrous
basis expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the moles of "R" present per mole of (Fe.sub.x
Al.sub.y P.sub.z)O.sub.2 and has a value of from zero to 0.3; and
"x", "y" and "z" represent the mole
fractions of the iron, aluminum and phosphorus, respectively, present
as tetrahedral oxides.
The instant invention relates to new molecular sieve compositions
having framework tetrahedral units of BeO.sub.2.sup.-2 AlO.sub.2.sup.-
and PO.sub.2.sup.+.
DESCRIPTION OF THE FIGURES
FIG. 1 is a ternary diagram wherein parameters relating to the
instant compositions are set forth as mole fractions.
FIG. 2 is a ternary diagram wherein parameters relating to preferred
compositions are set forth as mole fractions.
FIG. 3 is a ternary diagram wherein parameters relating to the
reaction mixtures employed in the preparation of the compositions
of this invention are set forth as mole fractions.
SUMMARY OF THE INVENTION
The instant invention relates to a new class of beryllium-aluminum-phosphorus-oxide
molecular sieves having a crystal framework structure of BeO.sub.2.sup.-2
AlO.sub.2.sup.- and PO.sub.2.sup.+ tetrahedral oxide units. These
new molecular sieves exhibit ion-exchange, adsorption and catalytic
properties and, accordingly, find wide use as adsorbents and catalysts.
The members of this novel class of compositions have crystal framework
structures of BeO.sub.2.sup.-2 AlO.sub.2.sup.- and PO.sub.2.sup.+
tetrahedral units and have an empirical chemical composition on
an anhydrous basis expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Be.sub.x Al.sub.y P.sub.z)O.sub.2 and has a value of zero to about
0.3; and "x", "y" and "z" represent
the mole fractions of beryllium, aluminum and phosphorus, respectively,
present as tetrahedral oxides. These molecular sieve compositions
comprise crystalline molecular sieves having a three-dimensional
microporous framework structure of BeO.sub.2.sup.-2 AlO.sub.2.sup.-
and PO.sub.2.sup.+ tetrahedral units.
The molecular sieves of the instant invention will be generally
referred to by the acronym "BeAPO" to designate the framework
of BeO.sub.2.sup.-2 AlO.sub.2.sup.- and PO.sub.2.sup.+ tetrahedral
units. Actual class members will be identified by denominating the
various structural species which make up the BeAPO class by assigning
a number and, accordingly, are identified as "BeAPO-i"
wherein "i" is an integer. The given species designation
is not intended to denote a similarity in structure to any other
species denominated by a numbering system.
DETAILED DESCRIPTION OF THE INVENTION
The instant invention relates to a new class of beryllium-aluminum-phosphorus-oxide
molecular sieves comprising a crystal framework structure of BeO.sub.2.sup.-2
AlO.sub.2.sup.- and PO.sub.2.sup.+ tetrahedral oxide units. These
new molecular sieves exhibit ion-exchange, adsorption and catalytic
properties and, accordingly, find wide use as adsorbents and catalysts.
The BeAPO molecular sieves have three-dimensional microporous framework
structures of BeO.sub.2.sup.-2 AlO.sub.2.sup.-, and PO.sub.2.sup.+
tetrahedral oxide units having an empirical chemical composition
on an anhydrous basis expressed by the formula:
wherein "R" represents at least one organic templating
agent present in the intracrystalline pore system; "m"
represents the molar amount of "R" present per mole of
(Be.sub.x Al.sub.y P.sub.z)O.sub.2 a value of zero to about 0.3
but is preferably not greater than about 0.15; and "x",
"y" and "z" represent the mole fractions of
beryllium, aluminum and phosphorus, respectively, present as tetrahedral
oxides. The mole fractions "x", "y", and "z"
are generally defined as being within the hexagonal compositional
area defined by points A, B, C, D, E and F of the ternary diagram
of FIG. 1. Points A, B, C, D, E and F of FIG. 1 have the following
values for "x", "y", and "z":
______________________________________ Mole Fraction Point x y
z ______________________________________ A 0.01 0.60 0.39 B 0.01
0.39 0.60 C 0.39 0.01 0.60 D 0.60 0.01 0.39 E 0.60 0.39 0.01 F 0.39
0.60 0.01 ______________________________________
In a preferred subclass of the BeAPO molecular sieves the values
of "x", "y" and "z" in the above formula
are within the tetragonal compositional area defined by the points
a, b, c and d of the ternary diagram which is FIG. 2 of the drawings,
said points a, b, c and d representing the following values for
"x", "y" and "z":
______________________________________ Mole Fraction Point x y
z ______________________________________ a 0.01 0.60 0.39 b 0.01
0.39 0.60 c 0.35 0.05 0.60 d 0.35 0.60 0.05 ______________________________________
In an especially preferred subclass of the BeAPO molecular sieves
the values of "x", "y" and "z" in
the formula are within the triangular compositional area defined
by the points e, f and g of the ternary diagram which is FIG. 2
of the drawings, said points e, f and g representing the following
values for "x", "y" and "z":
______________________________________ Mole Fraction Point x y
z ______________________________________ e 0.02 0.46 0.52 f 0.10
0.38 0.52 g 0.10 0.46 0.44 ______________________________________
The BeAPOs of this invention are useful as adsorbents, catalysts,
ion-exchangers, and the like in much the same fashion as aluminosilicates
have been employed heretofore, although their chemical and physical
properties are not necessarily similar to those observed for aluminosilicates.
BeAPO compositions are generally synthesized by hydrothermal crystallization
from a reaction mixture containing reactive sources of beryllium,
aluminum and phosphorus, preferably an organic templating, i.e.,
structure-directing, agent, preferably a compound of an element
of Group VA of the Periodic Table, and/or optionally an alkali or
other metal. The reaction mixture is generally placed in a sealed
pressure vessel, preferably lined with an inert plastic material
such as polytetrafluoroethylene and heated, preferably under autogenous
pressure, at a temperature between 50.degree. and 250.degree. C.,
and preferably between 100.degree. C. and 200.degree. C., until
crystals of the BeAPO product are obtained, usually a period of
from several hours to several weeks. Typical crystallization times
are from about 2 hours to about 30 days with from about 4 hours
to about 14 days, and preferably about 1 to about 7 days, being
generally employed to obtain crystals of the BeAPO products The
product is recovered by any convenient method such as centrifugation
or filtration.
In synthesizing the BeAPO compositions of the instant invention,
it is preferred to employ a reaction mixture composition expressed
in terms of the molar ratios as follows:
wherein "R" is an organic templating agent; "a"
is the amount of organic templating agent "R" and has
a value of from zero to about 6 and is preferably an effective amount
within the range of greater than zero (0) to about 6 and most preferably
not more than about 1.5; "b" has a value of from zero
(0) to about 500 preferably between about 2 and about 300 most
preferably not more than about 50; and "u", "v"
and "w" represent the mole fractions of beryllium, aluminum
and phosphorus, respectively, and each has a value of at least 0.01.
The mole fractions "u", "v" and "w"
in the reaction mixture are preferably within the pentagonal compositional
area defined by points G, H, I, J and K which is shown in FIG. 3
of the drawings, where points G, H, I, J and K have the following
values for "u", "v" and "w":
______________________________________ Mole Fraction Point u v
w ______________________________________ G 0.01 0.60 0.39 H 0.01
0.39 0.60 I 0.39 0.01 0.60 J 0.98 0.01 0.01 K 0.39 0.60 0.01 ______________________________________
Especially preferred reaction mixture compositions are those within
the pentagonal compositional area defined by points g, h, i, j and
k which is shown in FIG. 3 of the drawings, where points g, h, i
j and k have the following values for "u", "v"
and "w":
______________________________________ Mole Fraction Point x y
z ______________________________________ g 0.04 0.46 0.50 h 0.16
0.34 0.50 i 0.17 0.34 0.49 j 0.17 0.43 0.40 k 0.14 0.46 0.40 ______________________________________
In the foregoing expression of the reaction composition, the reactants
are normalized with respect to the total of u+v+w=1.00 mole, whereas
in the examples the reaction mixtures are expressed in terms of
the molar oxide ratios and may be normalized to 1.00 mole of P.sub.2
O.sub.5. This latter form is readily converted to the former form
by routine calculation by dividing the total number of moles of
beryllium, aluminum and phosphorus into the moles of each of beryllium,
aluminum and phosphorus. The moles of template and water are similarly
normalized.
In forming the reaction mixture from which the instant molecular
sieves are formed the organic templating agent can be any of these
heretofore proposed for use in the synthesis of conventional zeolite
aluminosilicates. In general these compounds contain elements of
Group VA of the Periodic Table of Elements, particularly nitrogen,
phosphorus, arsenic and antimony, preferably nitrogen or phosphorus
and most preferably nitrogen, which compounds also contain at least
one alkyl or aryl group having from 1 to 8 carbon atoms. Particularly
preferred compounds for use as templating agents are the amines,
quaternary phosphonium and quaternary ammonium compounds, the latter
being represented generally by the formula R.sub.4 X.sup.+ wherein
"X" is nitrogen or phosphorus and each R is an alkyl or
aryl group containing from 1 to 8 carbon atoms. Polymeric quaternary
ammonium salts such as [(C.sub.14 H.sub.32 N.sub.2)(OH).sub.2 ].sub.x
wherein "x" has a value of at least 2 are also suitably
employed. The mono-, di- and tri-amines are advantageously utilized,
either alone or in combination with a quaternary ammonium compound
or other templating compound. Mixtures of two or more templating
agents can either produce mixtures of the desired BeAPOs or the
more strongly directing templating species may control the course
of the reaction with the other templating species serving primarily
to establish the pH conditions of the reaction gel. Representative
templating agents include tetramethylammonium, tetraethylammonium,
tetrapropylammonium or tetrabutylammonium ions; tetrapentylammonium
ion; di-n-propylamine; tripropylamine; triethylamine; triethanolamine;
piperidine; cyclohexylamine; 2-methylpyridine; N,N-dimethylbenzylamine;
N,N-dimethylethanolamine; choline; N,N'-dimethylpiperazine; 14-diazabicyclo
(222) octane; N-methyldiethanolamine, N-methylethanolamine; N-methylpiperidine;
3-methylpiperidine; N-methylcyclohexylamine; 3-methylpyridine; 4-methylpyridine;
quinuclidine; N,N'-dimethyl-14-diazabicyclo (222) octane ion;
di-n-butylamine; neopentylamine; di-n-pentylamine; isopropylamine;
t-butylamine; ethylenediamine; pyrrolidine; and 2-imidazolidone.
Not every templating agent will direct the formation of every species
of BeAPO, i.e., a single templating agent can, with proper manipulation
of the reaction condition, direct the formation of several BeAPO
compositions, and a given BeAPO composition can be produced using
several different templating agents.
The reactive phosphorus source is preferably phosphoric acid, but
organic phosphates such as triethyl phosphate may be satisfactory,
and so also may crystalline or amorphous aluminophosphates such
as the AlPO.sub.4 composition of U.S. Pat. No. 4310440. Organo-phosphorus
compounds, such as tetrabutylphosphonium bromide, do not apparently
serve as reactive sources of phosphorus, but these compounds may
function as templating agents. Conventional phosphorus salts such
as sodium metaphosphate, may be used, at least in part, as the phosphorus
source, but are not preferred.
The preferred aluminum source is either an aluminum alkoxide, such
as aluminum isoproproxide, or pseudoboehmite. The crystalline or
amorphous aluminophosphates which are a suitable source of phosphorus
are, of course, also suitable sources of aluminum. Other sources
of aluminum used in zeolite synthesis, such as gibbsite, sodium
aluminate and aluminum trichloride, can be employed but are not
preferred.
The reactive source of beryllium can be introduced into the reaction
system in any form which permits the formation in situ of a reactive
form of beryllium, i.e., reactive to form the framework tetrahedral
oxide unit of beryllium. Compounds of beryllium which may be employed
include oxides, alkoxides, hydroxides, chlorides, bromides, iodides,
nitrates, sulfates, carboxylates (e.g., acetates) and the like.
While not essential to the synthesis of BeAPO compositions, stirring
or other moderate agitation of the reaction mixture and/or seeding
the reaction mixture with seed crystals of either the BeAPO species
to be produced or a topologically similar aluminophosphate, aluminosilicate
or molecular sieve composition, facilitates the crystallization
procedure.
After crystallization the BeAPO product may be isolated and advantageously
washed with water and dried in air. The as-synthesized BeAPO generally
contains within its internal pore system at least one form of the
templating agent employed in its formation. Most commonly the organic
moiety is present, at least in part, as a charge-balancing cation
as is generally the case with as-synthesized aluminosilicate zeolites
prepared from organic-containing reaction systems. It is possible,
however, that some or all of the organic moiety is an occluded molecular
species in a particular BeAPO species. As a general rule the templating
agent, and hence the occluded organic species, is too large to move
freely through the pore system of the BeAPO product and must be
removed by calcining the BeAPO at temperatures of 200.degree. C.
to 700.degree. C., preferably about 350.degree. C. to about 600.degree.
C., to thermally degrade the organic species. In a few instances
the pores of the BeAPO product are sufficiently large to permit
transport of the templating agent, particularly if the latter is
a small molecule, and accordingly complete or partial removal thereof
can be accomplished by conventional desorption procedures such as
carried out in the case of zeolites. It will be understood that
the term "as-synthesized" as used herein does not include
the condition of the BeAPO phase wherein the organic moiety occupying
the intracrystalline pore system as a result of the hydrothermal
crystalline process has been reduced by post-synthesis treatment
such that the value of "m" in the composition formula
has a value of less than 0.02. The other symbols of the formula
are as defined hereinabove. In those preparations in which an alkoxide
is employed as the source of beryllium, aluminum or phosphorus,
the corresponding alcohol is necessarily present in the reaction
mixture since it is a hydrolysis product of the alkoxide. It has
not been determined whether this alcohol participates in the synthesis
process as a templating agent. For the purposes of this application,
however, this alcohol is arbitrarily omitted from the class of templating
agents, even if it is present in the as synthesized BeAPO material.
Since the present BeAPO compositions are formed from BeO.sub.2
AlO.sub.2 PO.sub.2 tetrahedral units which, respectively, have
a net charge of -2 -1 and +1 the matter of cation exchangeability
is considerably more complicated than in the case of zeolitic molecular
sieves in which, ideally, there is a stoichiometric relationship
between AlO.sub.2.sup.- tetrahedra and charge-balancing cations.
In the instant compositions, an AlO.sub.2.sup.- can be balanced
electrically either by association with a PO.sub.2.sup.+ tetrahedron
or a simple cation such as an alkali metal cation, a cation of beryllium
present in the reaction mixture, or an organic cation derived from
the templating agent. Similarly, a BeO.sub.2.sup.-2 tetrahedron
can be balanced electrically by association with PO.sub.2.sup.+
tetrahedra, a cation of beryllium present in the reaction mixture,
a simple cation such as an alkali metal cation, organic cations
derived from the templating agent, or other divalent or polyvalent
metal cations introduced from an extraneous source. It has also
been postulated that non-adjacent AlO.sub.2.sup.- and PO.sub.2.sup.+
tetrahedral pairs can be balanced by Na.sup.+ and OH.sup.- respectively
[Flanigen and Grose, Molecular Sieve Zeolites-I, ACS, Washington,
D.C. (1971)].
The BeAPO compositions of the present invention may exhibit cation-exchange
capacity when analyzed using ion-exchange techniques heretofore
employed with zeolitic aluminosilicates and have pore diameters
which are inherent in the lattice structure of each species and
which are at least about 3 .ANG. in diameter. Ion exchange of BeAPO
compositions is ordinarily possible only after any organic moiety
derived from the template, present as a result of synthesis, has
been removed from the pore system. Dehydration to remove water present
in the as synthesized BeAPO compositions can usually be accomplished,
to some degree at least, in the usual manner without removal of
the organic moiety, but the absence of the organic species greatly
facilitates adsorption and desorption procedures. The BeAPO materials
have various degrees of hydrothermal and thermal stability, some
being quite remarkable in this regard, and function well as molecular
sieve adsorbents and hydrocarbon conversion catalysts or catalyst
bases.
In preparing the BeAPO composition it is preferred to use a stainless
steel reaction vessel lined with an inert plastic material, e.g.,
polytetrafluoroethylene, to avoid contamination of the reaction
mixture. In general, the final reaction mixture from which each
BeAPO composition is crystallized is prepared by forming mixtures
of less than all of the reagents and thereafter incorporating into
these mixtures additional reagents either singly or in the form
of other intermediate mixtures of two or more reagents. In some
instances the reagents admixed retain their identity in the intermediate
mixture and in other cases some or all of the reagents are involved
in chemical reactions to produce new reagents. The term "mixture"
is applied in both cases. Further, it ia preferred that the intermediate
mixtures as well as the final reaction mixtures be stirred until
substantially homogeneous. X-ray patterns of reaction products are
obtained by X-ray analysis using either: (1) two computer interfaced
Seimen's D-500 X-ray powder diffractometers, available from Seimens
Corporation, Cherry Hill, N.J., equipped wit Seimens Type K-805
X-ray sources; or (2) standard X-ray powder diffraction techniques.
When the standard technique is employed the radiation source is
a high-intensity, copper target, X-ray tube operated at 50 Kv and
40 ma. The diffraction pattern from the copper K-alpha radiation
and graphite monochromator is suitably recorded by an X-ray spectrometer
scintillation counter, pulse height analyzer and strip chart recorder.
X-ray patterns are obtained using flat compressed powder samples
which are scanned at 2.degree. (2 theta) per minute, using a two
second time constant.
All interplanar spacings (d) in Angstrom units are obtained from
the position of the diffraction peaks expressed as 2.theta. where
.theta. is the Bragg angle as observed on the strip chart. Intensities
are determined from the heights of diffraction peaks after subtracting
background, "I.sub.o " being the intensity of the strongest
line or peak, and "I" being the intensity of each of the
other peaks.
As will be understood by those skilled in the art the determination
of the parameter 2 theta is subject to both human and mechanical
error, which in combination, can impose an uncertainty of about
.+-.0.4.degree. on each reported value of 2 theta. This uncertainty
is, of course, also manifested in the reported values of the d-spacings,
which are calculated from the 2 theta values. This imprecision is
general throughout the art and is not sufficient to preclude the
differentiation of the present crystalline materials from each other
and from the compositions of the prior art. In some of the X-ray
patterns reported, the relative intensities of the d-spacings are
indicated by the notations vs, s, m, w and vw which represent very
strong, strong, medium, weak and very weak, respectively.
In certain instances the purity of a synthesized product may be
assessed with reference to its X-ray powder diffraction pattern.
Thus, for example, if a sample is stated to be pure, it is intended
only that the X-ray pattern of the sample is free of lines attributable
to crystalline impurities, not that there are no amorphous materials
present.
The molecular sieves of the instant invention may be characterized
by their X-ray powder diffraction patterns and as such may have
one of the X-ray patterns set forth in the following Tables A through
V, wherein said X-ray patterns are for the as-synthesized form unless
otherwise noted. In most cases, the pattern of the corresponding
calcined form will also fall within the relevant Table. However,
in some cases the removal of the occluded templating agent which
occurs during calcination will be accompanied by sufficient relaxation
of the lattice to shift some of the lines slightly outside the ranges
specified in the relevant Table. In a small number of cases calcination
appears to cause more substantial distortions in the crystal lattice,
and hence more significant changes in the X-ray powder diffraction
pattern. |