Crystalline molecular sieves and their synthesis.

摘要

A synthetic crystalline siliceous molecular sieve material has the structure of zeolite ZSM-5, zeolite ZSM-11 or zeolite ZSM-12 and contains aluminum and at least two elements selected from the group consisting of boron, gallium and iron in its anionic framework. The crystalline material has a composition on an anhydrous basis and in terms of moles of oxides per mole of silica expressed the the formula: a R2/nO : b Fe2O3 : c B2O3 : d Ga2O3 : e Al2O3 : SiO2 wherein R is at least one cation having the valence n, and a = (1.0+/-0.2)(b+c+d+e) b = 0 to 0.05 c = 0 to 0.05 d = 0 to 0.05 e = 0.00003 to 0.02 b+c+d+e = 0.005 to 0.05 b+c+d is not less than 0.00047 and wherein only one of b, c and d can be 0. When in the ammonium form, the crystalline material has a TPAD (temperature-programmed ammonia desorption) peak of from greater than 300 DEG C to less than 390 DEG C and a TPAD half-height width from greater than 135 DEG C to less than 155 DEG C.