硫酸化介孔Al-MCM-41的制备及其对苯甲醚乙酰化的催化性能

Synthesis of Sulphated Mesoporous Al-MCM-41 and Its Catalytic Application in Acetylation of Methoxybenzenes

通过水热合成法制备出不同Si/Al比的介孔分子筛Al-MCM-41,并用浸渍法制得SO42-/Al-MCM-41固体酸催化剂.利用XRD、N2吸附、红外、吡啶吸附红外等手段对其进行了表征.吡啶吸附红外分析发现催化剂存在质子酸活性中心,而无路易斯酸活性中心.将该固体酸催化剂分别用于1,4-二甲氧基苯和苯甲醚的乙酰化反应,考察了催化剂用量、反应温度、反应时间和底物与乙酸酐的配比等因素对底物转化率和产品选择性的影响.在优化反应条件下,SO42-/Al-MCM-41(30)催化苯甲醚乙酰化反应的转化率达到80.6%,选择性为94%.

Mesoporous molecular sieves （Al-MCM-41s） from MCM-41 incorporated with different aluminum content were synthesized through the hydrothermal method. The obtained Al-MCM-41 samples were impregnated with sulfuric acid and calcinated to afford the sulphated mesoporous Al-MCM-41 （SO4^2-/ Al-MCM-41） solid acids. The solid acids were characterized by XRD, N2-adsorption, FT-IR, and FT- IR of adsorbed pyridine techniques. Only Brqnsted acid sites were observed from the FT-IR spectrum of adsorbed pyridine. The solid acids were applied to the acetylation of 1,4-dimethoxybenzene and anisole re- spectively, and showed higher activity than the traditional solid acids. The factors which influenced the performance of the SO42/Al-MCM-41（30） （Si/Al=30） were investigated. A total conversion of 80.6% and a selectivity of 94.0% towards p-methoxyacetophenone were received catalyzed by SO4^2-/Al-MCM-41（30） under optimized reaction conditions.