助剂W改性α-氧化铝载体对乙烯环氧化银催化剂性能的影响  

Effect of W auxiliary modified α-alumina support on performance of silver catalyst for epoxidation of ethylene

作　　者：孙欣欣 SUN Xin-xin(Sinopec Beijing Research Institute of Chemical Industry,Beijing 100013,China)

机构地区：[1]中国石化北京化工研究院,北京100013

出　　处：《现代化工》2020年第7期175-179,共5页Modern Chemical Industry

基　　金：中国石化资助项目(471001-5)。

摘　　要：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 ofα-alumina supports modified with W compound are prepared,and the effect ofα-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 ofα-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 ofα-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 modifiedα-alumina support.The optimum adding amount of W auxiliary inα-alumina supports is found for excellent selectivity of the catalyst.

关 键 词：载体 改性 银催化剂 乙烯环氧化 活性 稳定性 

分 类 号：TQ032.41[化学工程]