Abstract: Using medium pore molecular sieve SAPO-11 and large pore zeolite β having various Si/Al ratios as active components, a series of catalysts containing composite molecular sieve or single molecular sieve were prepared. The catalysts were characterized by BET, XRD, NH3-TPD and FT-IR techniques. The hydroisomerization activity and selectivity of the catalyst were studied and compared using hexadecane as model compound. Test results showed that catalyst containing β(700) and SAPO-11 composite molecular sieve exhibited good hydroisomerization performance, the yield of multi-branched chain isohydrocanbons increased significantly and the isohydrocanbon yield could keep relatively high with the increase of reaction temperature. The characterization results showed that not only the types of molecular sieve but also the relative acidities of the molecular sieves could have a synergetic effect on catalyst.

Key words: composite molecular sieve, synergism, hydroisomerization, acidity