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用化学气相沉积法制备了Ti/HMS介孔分子筛催化剂,并对其进行甲基接枝改性.用XRD、N2-吸附、ICP-AES、FTIR,UV-vis和29SiCP/MAS NMR等手段对样品进行了表征,考察了催化剂的丙烯环氧化性能.结果表明:气相沉积法载钛和接枝改性减小了HMS分子筛表面的孔径和比表面,但是分子筛的介孔特征仍然保持;随着沉积时间的增加(0.5～2h),催化剂的钛含量逐渐增加,催化活性也随之增加,但当沉积时间超过2h后,钛含量和催化活性均保持不变;接枝改性后催化剂的环氧化活性和选择性均显著提高;气相沉积法合成Ti/HMS比水热法合成Ti-HMS具有更高的环氧化催化活性.
The Ti / HMS mesoporous molecular sieve catalyst was prepared by chemical vapor deposition, and its methyl group was modified by methyl. The effects of XRD, N2-adsorption, ICP-AES, FTIR, UV-vis and 29SiCP / MAS NMR on Samples were characterized and investigated for epoxidation of propylene.The results showed that the titania and graft modification by vapor deposition reduced the pore size and specific surface area of HMS zeolite, With the increase of deposition time (0.5 ~ 2 h), the titanium content of the catalyst gradually increases and the catalytic activity also increases, but when the deposition time exceeds 2 h, the titanium content and the catalytic activity remain unchanged; Epoxidation activity and selectivity were significantly increased. Ti / HMS synthesized by vapor deposition had higher epoxidation catalytic activity than hydrothermal synthesis of Ti-HMS.