以氯铂酸为Pt前驱体，分别以丙酮、水及氨水为溶剂，采用等体积浸渍法制备了质量分数为0.3%的Pt/ZSM-5催化剂，考察了不同溶剂对Pt/ZSM-5催化剂在高压、低水、低氢及低甲苯甲醇比的反应条件下的甲苯甲醇烷基化反应稳定性的影响。利用XRD、SEM、N₂吸附-脱附、NH₃-TPD和TG等表征方法对催化剂进行了表征。结果表明，以丙酮为溶剂负载Pt，不会影响对二甲苯的选择性，但Pt的加氢能力较差、稳定性欠佳，反应55 h后，活性仅为初始活性的54.4%；以水为溶剂负载Pt，对二甲苯选择性略微降低，其加氢能力增强，反应55 h时可保持初始活性的78.0%；以氨水为溶剂负载Pt，对二甲苯选择性略微降低，其Pt物种分散度更高，距离活性中心更近，故其加氢能力最为优异，稳定性显著提高，反应200 h仍可保持初始活性的81.4%。

Pt/ZSM-5 catalysts with 0.3 wt% loading is prepared via incipient wetness impregnation method with chloroplatinic acid as precursor,and using acetone,water and ammonium hydroxide as solvents,respectively.The effects of solvent on the stability of Pt/ZSM-5 in alkylation of toluene with methanol are investigated under the reaction conditions of high pressure,low water,low hydrogen and low ratio of toluene to methanol.Pt/ZSM-5 catalysts are characterized by XRD,SEM,N₂ adsorption-desorption,NH₃-TPD and TG.Results show that as Pt is loaded with acetone as solvent,there is no impact on the catalyst's selectivity for p-xylene,both the hydrogenation ability and stability of Pt are poor,and the catalyst's activity remains only 54.4% of the initial activity after 55 hours of reactions.As Pt is loaded with water as solvent,the catalyst's selectivity for p-xylene drops slightly,its hydrogenation ability is slightly stronger,and its activity maintains 78.0% of the initial activity after 55 hours of reaction.In addition,as Pt is loaded with ammonium hydroxide as solvent,the catalyst's selectivity for p-xylene drops slightly,Pt species dispersion in the catalyst is higher and closer to active centers,so the catalyst's hydrogenation ability is the best,and its stability is significantly improved.Its activity keeps still 81.4% of the initial activity after 200 hours of reaction.

赵成浩(1996-),男,硕士研究生,研究方向为分子筛合成、改性及工业化应用,zch042796@163.com;张安峰(1978-),男,博士,副教授,硕士生导师,研究方向为分子筛催化,通讯联系人,zhangaf@dlut.edu.cn。