Synthesis and Catalytic Performance of Core-shell Micro-Mesoporous Composite Zeolite MCM-41@TS-1 Catalysts

To solve the problem of a narrow pore applicability of zeolite molecular sieves with MFI topology (TS-1), a core-shell mesoporous composite molecular sieve xMCM-41@TS-1 was synthesized by an in-situ crystallization method. The results show that xMCM-41@TS-1 has a well-crystallized microporous core and mesoporous shell with regular pores, thus effectively improving the reaction mass transfer efficiency, reducing the diffusion resistance, and promoting the effective utilization of active titanium centers. Also, the core-shell mesoporous composite structure is beneficial to shortening the diffusion path of the material, so that the carbon deposition precursor in the microporous can diffuse to the surface in time. According to the catalytic performance results, the catalytic activity of xMCM-41-41@TS-1 in butadiene epoxidation and cyclohexane oxidation can reach 3 times and 2 times greater than that of TS-1, respectively, and the cycle stability is greater than that of TS-1.