沉淀剂对Au/CeO2催化剂乙醇部分氧化制氢性能的影响

摘要

Au/CeO2 catalysts were prepared by deposition-precipitation method, using four precipitants Na2CO3 ,CO(NHZ)2 ,NaOH and NH4OH. Their catalytic performance for ethanol partial oxidation reaction was investigated by means of XRD,TPR,ICP and BET techniques. The results revealed that the Au/CeO2 catalysts prepared by using CO(NH2)2 and Na2CO3 as the precipitant exhibited higher activity,while the sample prepared only by CO(NH2)2 showed higher Hydrogen selectivity and comparatively lower CO selectivity. The activity of catalyst samples prepared by different precipitants were closely related with BET surface area,particle size,pore size distribution, Au loading and difficult degree of CeO2 reduction.%选择了4种沉淀剂Na2CO3,CO(NH2)2,NaOH和NH4OH,通过沉积-沉淀法分别制备Au/CeO2催化剂.以乙醇部分氧化制氢为探针反应,研究不同沉淀剂对Au/CeO2催化剂乙醇部分氧化性能的影响,并运用XRD,TPR,BET,ICP等方法对催化剂进行表征,探讨了不同沉淀剂影响Au/CeO2催化剂乙醇部分氧化性能的原因.结果表明,以CO(NH2)2和Na2CO3为沉淀剂制备催化剂具有较好的乙醇部分氧化制氢活性,以CO(NH2)2为沉淀剂制备的催化剂具有更高的氢选择性,较低的CO选择性.不同沉淀剂制备的催化剂的活性与其比表面积、粒径大小、孔径分布、金负载量、CeO2还原的难易程度密切相关.