微孔/微介孔H-ZSM-5分子筛上甲苯甲醇的烷基化性能

Catalytic Performance of Micro-/micro-mesoporous H-ZSM-5 Zeolites for Alkylation of Toluene with Methanol

以不同硅铝比的H-ZSM-5分子筛为研究对象,考察了Na OH碱处理、酒石酸处理及Na OH碱处理-酒石酸处理相结合的方法对其物化性能和催化性能的影响.处理前后分子筛的表征结果表明,酸处理和碱处理可通过调变催化剂的酸性和孔道结构影响其催化性能.酸处理对低硅铝比H-ZSM-5的酸性和催化性能影响较大,而碱处理则主要影响高硅铝比分子筛的酸性和催化性能.酸处理和碱处理相结合则能同时调变分子筛的酸性和孔道结构,进而提高其在甲苯甲醇制二甲苯反应中的催化活性.其中,碱处理的高硅铝比H-ZSM-5分子筛表现出最优异的催化活性.

The effects of acid or alkali treatments as well as acid-alkali treatment on the physicochemical properties and catalytic performances in the alkylation of toluene with methanol over H-ZSM-5 zeolites with different Si/Al ratios were investigated. The zeolites before and after the treatment were characterized by XRD,NH3-TPD,BET and TEM. The results indicated that the acid and alkali treatment had the great effects on the acidity and pore structure of the zeolites,which can directly influence the catalytic activities of the zeolites.Acid treatment can greatly influence the acidity and catalytic activities of H-ZSM-5 with lower Si/Al ratios,while alkali treatment only had the great effects on H-ZSM-5 with higher Si/Al ratios. The combination of acid and alkali treatment can adjust the acidity and pore structures of the zeolites simultaneously,and then enhance the catalytic activity in the alkylation of toluene with methanol.