【摘要】 采用柠檬酸法制备了Ce-Zr-O2固溶体,并负载了过渡金属和贵金属Pt,其中,以Cu作为活性组分,在CO氧化反应中表现出最高的活性,CO完全转化的温度约为120℃,明显高于负载1%Pt(质量分数)催化剂的活性.掺杂少量Zr到Ce O2(Ce0.8Zr0.2O2)中对Cu基催化剂有非常好的促进作用.分别采用等体积浸渍法(IW)、沉淀沉积法(DP)、水热法(HT)以及柠檬酸法(CA)制备了Cu负载质量分数为20%的Cu/Ce0.8Zr0.2O2催化剂.结果表明,由沉淀沉积法制备的Cu/Ce0.8Zr0.2O2催化剂的活性最高,在100℃时,CO可完全转化.TEM结果表明,Cu O物种很好地分散在Ce0.8Zr0.2O2上.吸附实验数据表明,Cu基催化剂上CO与O2之间较弱的竞争吸附是其活性高于Pt催化剂的主要原因.Cu基催化剂上的氧空位对促进O2的吸附具有重要作用,也是影响CO低温氧化的重要因素之一.更多还原

【Abstract】 Ce-Zr-O2 solid solution was prepared by citric acid method and 10%M / Ce0. 8Zr0. 2O2( M=Co,Mn,Cu) and 1% Pt / Ce0. 8Zr0. 2O2 were prepared by incipient-wetness impregnation method. It was found that Cu was the best active composition in CO oxidation over M / Ce0. 8Zr0. 2O2,which CO was completely converted into CO2 at ca. 120 ℃ and was more active than 1%Pt / Ce0. 8Zr0. 2O2. It was found that the optimum ratio of Ce to Zr was 4,Cu / Ce0. 8Zr0. 2O2 showed the best activity in CO oxidation. Deposition method( DP),incipient-wetness precipitation method( IW),hydro-thermal method( HT) and citric acid method( CA) were used to prepare 20%Cu / Ce0. 8Zr0. 2O2 catalysts. Cu / Ce0. 8Zr0. 2O2 prepared by deposition method showed better activity in CO oxidation,which CO was completely converted into CO2 at ca. 100 ℃. The data from H2-TPR showed that the redox of Cu / Ce0. 8Zr0. 2O2 was not a determining factor to control the CO oxidation. TEM results showed that the Cu O was well dispersed on Ce0. 8Zr0. 2O2. Based on adsorption data of CO and O2,the high activity of Cu-based catalyst should be ascribed to the week competitive adsorption between CO and O2 over Cu / Ce0. 8Zr0. 2O2.The oxygen vacancy on Ce0. 8Zr0. 2O2 was a crucial factor to affect the Cu O dispersion and to reduce the competitive adsorption between CO and O2.更多还原