The Influence of Silicon and Aluminum Species on Physicochemical Properties and Catalytic Perfermance of SAPO-31 Molecular Sieve

Abstract

A series of SAPO-31 molecular sieves were synthesized by hydrothermal method with fumed silica and silica sol as silicon source and aluminium isopropoxide and pseudoboehmite as aluminum source,respectively.The influence of silicon and aluminum species used in synthesis on the structure and acidic properties of synthesized SAPO-31 were investigated by the methods of XRD,XRF,N_2 physical adsorption,SEM,NH_3-TPD and Py-IR.The catalytic performance of the Pd/SAPO-31 bifunctional catalysts in n-decane hydroisomerization was evaluated.The results indicated that with silica sol as silicon source and pseudoboehmite as aluminum source,the synthesized SAPO-31 possessed an essence of larger specific surface area and micropore volume,catalyzed by which the n-decane hydroisomerization was excellent carried out with the selectivity of90.3%for i-decane at n-decane conversion of 90.0%.