Investigations on the CoAPO-36 molecular sieve

Highly crystalline cobalt aluminophosphates of type 36 have been synthesized and characterized. Investigations on the thermal decomposition of Pr₃N-CoAPO-36 and the surface, sorption, acid strength distribution, acidic and catalytic properties of CoAPO-36 were carried out. The XPS analysis indicated that the concentration of cobalt was higher in the bulk of the material than on the surface. The surface of the cobalt aluminophosphate is aluminium rich. The number of strong acid sites is higher on the CoAPO-36 than on CoAPO-5, MAPO-5 and ZAPO-36. The catalytic activities of CoAPO-5, MAPO-5, ZAPO-36, CoAPO-36, MAPO-36 and MAPSO-36 in the 3-methylpentane ando-xylene conversion reactions were compared. The catalytic turnover rate per framework substituted atom in the conversion ofo-xylene for CoAPO-36 is higher than for the MAPO-5, CoAPO-5, ZAPO-36 and MAPSO-36. In the ethylbenzene conversion reaction, the deactivation of the cobalt aluminophosphate and magnesium aluminophosphates of type 36 were studied.