Ag改性Pd基催化剂的C_4烃选择加氢性能  

Ag promoted Pd-based catalyst for selective hydrogenation of C_4 fraction

作　　者：赵多 刘仲能 周兴贵[1] 袁渭康[1] 

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237 [2]中国石化上海石油化工研究院绿色化工与工业催化国家重点实验室,上海201208

出　　处：《石油化工》2017年第11期1361-1365,共5页Petrochemical Technology

摘　　要：研究了Ag改性Pd/Al_2O_3催化剂的碳四烃选择加氢性能,考察了助剂Ag及其负载量对催化剂活性和选择性的影响。实验结果表明,Ag助剂能明显改善Pd/Al_2O_3催化剂的选择加氢性能,提高丁二烯加氢转化率和丁烯-1收率;采用Ag负载量0.3%(w)的Pd-Ag/Al_2O_3催化剂,在温度40℃、氢气压力2.0 MPa、氢气/丁二烯摩尔比20的条件下,产物中剩余丁二烯含量小于10×10^(-6)(w)、丁烯-1收率达96.8%。采用H_2-O_2滴定、XPS、EDX及H_2-TPR等方法对催化剂进行表征。表征结果显示,双金属Pd-Ag/Al_2O_3催化剂上金属间存在较强相互作用,改变了Pd在催化剂上的几何分布状态及电子性质;引入Ag使Pd催化剂上金属Pd的分散度及电子云密度降低,β-PdH生成量减小。Pd-Ag/Al_2O_3催化剂的催化加氢行为得到改善,丁二烯转化率和丁烯-1收率同时增加。The selective hydrogenation of C4 fraction was investigated over Ag promoted Pd-based catalyst was placed on exploring the role of Ag and its content on the catalytic activity and selectivity of the catalyst. The results showed that Ag could significantly enhance activity and selectivity of the Pd-based catalysts in the selective hydrogenation of C4 fraction, and increased the conversion ratio of butadiene and the yield ratio of 1-butene. With butadiene residue of lower than 10 × 10-6（w）, 1-butene yield of 96.8% was obtained over the catalyst with 0.3%（w） Ag content under the operation conditions： temperature of 40 ℃, hydrogen pressure of 2.0 MPa and mole fraction ratio of C4 to H2 20. The prepared catalysts were characterized by H2-O2 titration, XPS, EDX and H2-TPR. The results indicated that strong interaction existed between Pd and Ag in the Pd-Ag bimetallic catalysts, which altered electronic or geometric properties of the Pd. The introduction of Ag obviously decreased the Pd dispersion and electronic density, leading to less forming amount of β-PdH. These changes resulted in the differences in the catalytic behavior of the catalyst towards the reactants, thus raising the butadiene conversion and the 1-butene yield.

关 键 词：钯催化剂 银 选择加氢 丁二烯 

分 类 号：TQ426.94[化学工程]