Silicoaluminophosphate crystallization using hydrolysis

A method for synthesizing crystalline silicophosphoaluminate, which method comprises:

• (1) providing a reaction mixture comprising water, sources of aluminum oxide, silicon oxide, and phosphorus oxide, one of the said oxide sources being unstable in the water, an organic directing agent A, inorganic cations M and anions N, and a substantially water-immiscible organic solvent for the said oxide source unstable in the water, the components of said reaction mixture having the following relationship:
• (A).sub.a :(M.sub.2 O).sub.b :(Al.sub.2 O.sub.3).sub.c :(SiO.sub.2).sub.d :(P.sub.2 O.sub.5).sub.e :(Solvent).sub.f :(N).sub.g :(H.sub.2 O).sub.h
• wherein a, b, c, d, e, f, g and h are numbers satisfying the following relationships:
• a/(c+d+e) is less than 4,
• b/(c+d+e) is less than 2
• d/(c+e) is less than 2,
• f/(c+d+e) is from 0.1 to 15,
• g/(c+d+e) is less than 2, and
• h/(c+d+e) is from 3 to 150,
• wherein upon initial provision of said reaction mixture the said oxide source unstable in the water is dispersed or dissolved in the water-immiscible organic solvent;
• (2) heating said reaction mixture at a rate of from 5.degree. C. to 200.degree. C. per hour to a temperature of from 80.degree. C. to 300.degree. C.;
• (3) agitating said reaction mixture in a manner sufficient to intimately admix the water-immiscible organic solvent and the water with each other, thereby progressively hydrolyzing the oxide source unstable in water;
• (4) maintaining said agitated reaction mixture at a temperature of from 80.degree. C. to 300.degree. C. and a pH of from 2 to 9 until crystals of silicophosphoaluminate material are formed;
• and
• (5) recovering from said reaction mixture silicophosphoaluminate material characterized by a composition, in the anhydrous state, as follows:
• A'.sub.v :M.sub.x/m.sup.m+ :(AlO.sub.2).sub.1-y.sup.- :(PO.sub.2).sub.1-x.sup.+ :(SiO.sub.2).sub.x+y :N.sub.y-n.sup.n-
• wherein A' represents the total of organic directing agent A plus organic solvent, v is the number of moles of A', m is the valence of cation M, n is the valence of anion N, and x and y are numbers of from greater than -1 to less than +1 which satisfy the relationships:
• (1) if x is 0, the y is not 0,
• (2) if y is 0, then x is not 0,
• (3) if the atomic ratio of Al/P is greater than 1, then (x+y) is greater than 0 and y+0.6x is less than 0.4, and
• (4) if the atomic ratio of Al/P is less than 1, then (x+y) is greater than 0 and 0.5 is greater than 0.5 y+x,
• said silicophosphoaluminate having an ion exchange capacity of at least about 0.002 meq/g.