载体对Au-Pd催化剂甲醇部分氧化制氢性能的影响

用PVP保护乙醇还原法制备了一系列Au-Pd/MOx(M=Zn、Ce、Fe、Ti、Cr和Al)双金属催化剂,考察了不同载体对Au-Pd催化剂甲醇部分氧化制氢性能的影响,用XRD、TG、TPD、TPR和TPH等对催化剂进行了表征。结果表明,载体对催化剂性能有较大影响,与钛、铬和铝氧化物载体相比,448K时偏碱性的锌、铈和铁氧化物载体负载的Au-Pd催化剂的甲醇转化率均在80.0%以上,催化剂积碳量降低。其中以Au-Pd/ZnO催化剂的效果最好,523K时甲醇转化率和氢气选择性分别为99.0%和45.6%,反应20h后积碳量仅为0.0232g/gcat.。

Effect of Supports on the Au-Pd Bimetallic Catalyst for Hydrogen Production by Partial Oxidation of Methanol

Hydrogen production by partial oxidation of methanol (POM) was investigated over Au-Pd/MOx(M=Zn,Ce,Fe,Ti,Cr and Al) bimetallic catalysts,prepared by PVP-stabilized reduction method by C2H5OH.The catalysts were characterized by XRD,TG,TPD,TPR and TPH analyses.The results indicated that the supports play an important role in the catalytic performance of catalysts.Compared with titanium,chromium and aluminum oxides,the alkalescent supports,such as zinc,cerium and iron oxides supported Au-Pd bimetallic catalysts gave the methanol conversion above 80% at 448 K,and the amount of carbon deposited could be decreased on alkalescent supports.The Au-Pd/ZnO catalyst showed the best catalytic performance.A high methanol conversion of 99.0% was attained at 523 K with 45.6% hydrogen selectivity for Au-Pd/ZnO catalyst,and the amount of carbon deposited was only 0.023 2 g/g cat. after reacting for 20 h.