Mg/Ce-SBA-15的制备及其苯酚甲醇烷基化性能的研究

以Ce-SBA-15为载体，硝酸镁为活性组分前驱体，通过浸渍法制备了Mg/Ce-SBA-15催化剂。利用XRD、N₂吸附-脱附、SEM、EDS、NH₃-TPD、Py-FTIR和TG-DTA手段对催化剂进行表征。结果表明，Mg掺杂并未破坏载体结构，催化剂表面弱酸含量有所增加，L酸增加明显。在固定床反应器中评价了Mg/Ce-SBA-15分子筛催化苯酚甲醇烷基化的反应性能。结果表明，Mg负载量为7%、焙烧温度为550℃、焙烧时间为4.5 h制备的Mg/Ce-SBA-15催化剂催化效果最佳。在反应温度460℃，n（苯酚）：n（甲醇）为1：4，质量空速为3.0 h^-1，常压的条件下，苯酚转化率为80.1%，邻甲酚选择性为86.4%。

Preparation of Mg/Ce-SBA-15 catalyst and its performance on phenol alkylation with methanol

Mg/Ce-SBA-15 mesoporous molecular sieves were synthesized by using Ce-SBA-15 as support and magnesium nitrate as precursor through impregnation method. The samples were characterized by XRD, N₂ adsorption-desorption, BET, SEM, NH₃-TPD, Py-FTIR and TG-DTA techniques. The results indicate that the original crystal structures of SBA-15 remain unchanged after modification with Mg, but the number of weak acids were increased especially L acids. The performances of catalysts in phenol alkylation with methanol were studied in a fixed bed reactor. The results showed that the catalyst showed the highest catalytic activity under the conditions of Mg content=7%, calcination temperature=550℃ and calcination time=4.5 h.At 460℃, n(phenol):n(methanol)=1:4, WHSV=3.0 h^-1 and atmospheric pressure, the conversion of phenol was 80.1% and the selectivity to o-cresol was 86.4%.