Microporous silicoaluminophosphates

VII. Investigations of Chemical Behavior and Local Structure of Surface Sites in Zeolites and Microporous Silicoaluminophosphates... 

In the preceding decade, microporous silicoaluminophosphates have drawn increasing interest as solid catalysts in chemical technology, because of their acidic and shape-selective properties. H-SAPO-34 with the chabasite structure, for example, is a suitable catalyst for the conversion of MTO (210). H-SAPO-37 with the faujasite structure was applied for the isomerization of -decane (211) and the isobutylene/2-butene alkylation (212). 

Synthesis of Microporous Silicoaluminophosphates in Hexanol—Water Biphasic Systems... 

Crystalline microporous silicoaluminophosphates have been patented as SAPO-n (1) or MCM-n (2) materials. The SAPO materials crystallize from an aqueous medium in the presence of organic templates, the MCM materials from a biphasic medium, using similar templates. Most of the actually known MCM s and SAPO s are crystallographically different apart from SAPO-34, SAPO-44, SAPO-47 and MCM-2 which have the chabasite topology (2,2) The structure of other MCM materials is presently unknown. 

From the available literature it appears that the Si, A1 and P ordering in the two groups of microporous silicoaluminophosphates should be different. The anhydrous chemical composition of SAPO-n corresponds to (1) ... 

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