化学镀法制备Pd负载型碳二馏分选择加氢催化剂及其催化性能

以Al2O3为载体,采用特殊的化学镀法制备了Pd负载型碳二馏分选择加氢催化剂。对催化剂表面进行X射线光电子能谱和扫描电子显微镜表征显示,活性组分Pd在催化剂表面以单质形式存在,在碳二馏分加氢反应前无须高温焙烧和还原,且Pd富集分布在催化剂表面壳层的10～20μm之间,与浸渍法制备的Pd负载型催化剂相比,Pd层更薄,有利于提高Pd的利用率。在气态空速15000h-1、氢气与乙炔摩尔比1.5、反应温度130℃的条件下,以碳二馏分选择加氢反应考察了催化剂的性能,评价结果表明,以化学镀法制备的HXD10催化剂的性能大大优于浸渍法制备的SAM20催化剂(两种催化剂中Pd质量分数均为0.035%),HXD催化剂上乙炔转化率和乙烯选择性分别达到91%和83%。

Supported Pd Catalyst Prepared by Electroless Plating for Selective Hydrogenation of C2 Fraction

The supported Pd catalyst was prepared by electroless plating with Al2O3 as support and used in selective hydrogenation of C2 fraction.The catalyst was characterized by means of XPS and SEM.The active component-Pd existed in simple metallic form on catalyst surface.The calcinations and reduction procedures of the catalyst could be omitted before the hydrogenation.The Pd was concentrated in a shell layer on catalyst surface with a thickness of 10-20 μm.The Pd shell layer was thinner on catalyst prepared by electroless plating than that by impregnation,which helped to save the consumption of precious metal Pd.The activity of the catalyst in selective hydrogenation of C2 fraction was evaluated under the conditions of GHSV 15 000 h-1,n(H2)∶n(C2H2)1.5 and reaction temperature 130 ℃.The activity of HXD10 catalyst prepared by electroless plating was much higher than that of SAM20 catalyst by impregnation.Pd mass fractions in both catalysts were 0.035%.The acetylene conversion of the former was 91% and selectivity to ethylene was 83%.