载体预处理工艺对乙烯氧化银催化剂性能的影响

采用预浸渍和预焙烧联合预处理工艺处理载体,制备系列乙烯氧化的银催化剂。对催化剂进行孔结构、吸水率和比表面积等表征,结果表明,预处理工艺能增加载体的比表面积,改善活性组分的分散状况并提高活性组分银的负载量,同时除去载体表面钠,预处理工艺制备的银催化剂活性、选择性和稳定性均得到改进。

Effect of carrier pre-treatment process on the performance of silver catalysts for ethylene oxidation

The carriers were treated by pre-impregnation and pre-calcination process, and a series of silvercatalysts for ethylene oxidation were prepared. In order to investigate the effects of pre-treatment on the performance of silver catalysts,the pore structures,water absorption and surface area were investigated,and the catalyst performances were evaluated by ethylene epoxidation reaction in the micro-reactor.The results indicated that pre-treatment could enhance the surface area of the carrier,improve the dispersion of active component and increase the silver loading amount,and simultaneously removed sodium from the surface of the carrier.The pre-treatment of the carrier could improve the activity,selectivity and stability of the silver catalyst.