制备了系列含W化合物的改性α-氧化铝载体，通过BET、XRD、SEM、XPS等研究了助剂W对α-氧化铝载体孔结构和形貌的影响，以及载体表面通过助剂W改性后对催化剂表面银粒尺寸、分布、形貌特征和银氧结合能的影响。结果表明，助剂W改性α-氧化铝载体后载体孔道变大、孔容增加，载体表面与银的作用增强，银粒分布更均匀，尺寸增长变缓，延长了银粒聚集时间。在微型固定床反应器中对催化剂进行长周期稳定性评价，结果表明，助剂W改性载体制备的银催化剂活性明显提高、稳定性显著改进，银催化剂的选择性与银粒子尺寸相关，为了获得较好的选择性需要控制助剂W加入量。

A series of α-alumina supports modified with W compound are prepared,and the effect of α-alumina supports modified by W auxiliary on the performance of Ag catalyst for ethylene epoxidation is studied.By means of BET,XRD,SEM,XPS and other characterization methods,the effect of W auxiliary on the morphology and pore structure of α-alumina support is studied.The effect of the surface modification of supports by W auxiliary on the size,distribution,shape,appearance characteristics,and silver-oxygen binding energy of the silver particles on the catalyst surface is studied.Study result indicates that W auxiliary can expand the channels and pore volume of α-alumina supports,enhance the interaction between silver and support surface,make the distribution of silver particles more uniform,slow the size growth,and prolong the aggregation time of silver particles.The long-term stability of the catalyst is evaluated in a micro fixed bed reactor,showing that the activity and stability of the Ag catalyst is significantly improved by W auxiliary modified α-alumina support.The optimum adding amount of W auxiliary in α-alumina supports is found for excellent selectivity of the catalyst.