Vapor-Phase Transport Synthesis of MnSAPO-34 and Its Catalytic Properties

摘要

MnSAPO-34 molecular sieves were synthesized by vapor-phase transport(VPT) method using triethylamine(Et3N) as a structure directing agent(SDA),and were characterized by XRD,BET,SEM,UV-Vis,FT-IR,and TG analyses.The influence of the zeolite crystallization conditions and the dry-gel composition were investigated.The results showed that the synthesis conditions had an effect on the crystalline phase.Pure MnSAPO-34 had been obtained when it was crystallized at 140℃ for 18 hours.The ratio of MnO/Al2O3 in the starting gel ranging from 0.1 to 0.2 resulted in pure MnSAPO-34 with a CHA topology.Beyond this scope,MnSAPO-5 with an AFI topology structure was obtained as an impurity substance.UV-Vis spectroscopy and FT-IR spectroscopy study indicated that manganese was incorporated into the framework of the molecular sieve.The catalytic performance of MnSAPO-34 molecular sieve was tested by ketalization reaction of 1,2-propanediol with cyclohexanone.High yield of cyclohexanone-1,2-propanediol ketal was obtained.