MAINTAINING ACID CATALYST SITES IN SAPO MOLECULAR SIEVES

摘要

This invention is directed to a molecular sieve having acid catalyst sites and a method of maintaining the acid catalyst sites of a template-containing silicoaluminophosphate molecular sieve. The method comprises providing a template-containing silicoaluminophosphate molecular sieve and heating the molecular sieve in an oxygen depleted environment under conditions effective to maintain or preserve the number of acid catalyst sites. The heated molecular sieve exhibits at least one peak in the infrared region in a range of from 3630 cm<-1> to 3580 cm<-1>. Preferably, the heated molecular sieve exhibits a combined peak area in the 3630 cm<-1> to 3580 cm<-1> range of at least 10 % of a total peak area of all peaks in an infrared region between 4000 cm<-1> to 3400 cm<-1>.