Cu-Zn-Zr催化剂用于苯甲酸甲酯加氢制苯甲醇的研究

Cu-Zn-Zr CATALYST FOR HYDROGENATION OF METHYL BENZOATE TO BENZYL ALCOHOL

采用共沉淀法制备了一系列Cu-Zn-Zr催化剂,考察了其对苯甲酸甲酯选择性加氢制苯甲醇的催化性能。当催化剂中Cu/Zn/Zr物质的量之比控制在5/6/4,并经过650℃高温焙烧后,其催化性能表现突出。为了进一步优化苯甲酸甲酯加氢制备苯甲醇的反应条件,在高压搅拌釜中考察了反应温度、反应压力及反应时间对反应性能的影响。结果表明,在反应温度160℃、压力7 MPa、反应时间10 h的条件下,苯甲酸甲酯的转化率为88.1%,苯甲醇的选择性可达95.21%。通过N_(2)吸附-脱附、X射线衍射、H_(2)程序升温还原、NH_(3)程序升温脱附、X射线光电子能谱、透射电子显微镜等手段对催化剂进行了表征,发现Zr元素的引入显著提升了苯甲醇的选择性;金属Cu纳米粒子的高度分散有利于提高催化剂的活性和稳定性;催化剂表面呈弱酸性有利于催化剂活性的提高。这些因素的协同作用使得催化剂在苯甲酸甲酯制苯乙醇反应中表现出优异的性能。

A series of Cu-Zn-Zr catalysts were synthesized by a co-precipitation method,and their catalytic performance for the selective hydrogenation of methyl benzoate to benzyl alcohol was experimentally evaluated.When the molar ratio of Cu/Zn/Zr was controlled at 5/6/4 and calcined at 650℃,the catalyst exhibited particularly prominent catalytic performance.In order to optimize the reaction conditions of methyl benzoate hydrogenation to benzyl alcohol,the effects of reaction temperature,reaction pressure and reaction time on the reaction performance were investigated in a high-pressure stirred tank.The results revealed that the conversion rate of methyl benzoate reached 88.1%and the selectivity for benzyl alcohol reached 95.21%at the conditions of a reaction temperature of 160℃,a pressure of 7 MPa and a reaction time of 10 h.The catalysts were characterized by N_(2)-adsorption desorption,XRD,H_(2)-TPR,NH_(3)-TPD,XPS and TEM,it was found that the introduction of Zr element significantly enhanced the selectivity for benzyl alcohol,and the high dispersion of metal copper nanoparticles beneficial to the activity and stability of the catalyst.The weak acidity of the catalyst surface favored the enhancement of catalytic activity.The synergy of these factors has led to the excellent performance of the catalysts in the methyl benzoate ethanol reaction.