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.
Ce-Zr-O2 solid solution was prepared by citric acid method and 10% M/Ce0. 8 Zr0. 2 O2 （M = Co, Mn, Cu） and 1% Pt/Ce0. 8 Zr0.2 O2 were prepared by incipient-wetness impregnation method. It was found that Cu was the best active composition in CO oxidation over M/Ce0. 8 Zr0. 2 O2, which CO was completely converted into CO2 at ca. 120 ℃ and was more active than 1% Pt/Ce0.8Zr0.2O2. It Zr was 4, Cu/Ce0. s Zr0.202 showed the best activity in CO oxidation. was found that the optimum ratio of Ce to Deposition method（ DP）, incipient-wetness precipitation method（IW）, hydro-thermal method （HT） and citric acid method（CA） were used to prepare 20% Cu/Ce0.8 Zr0. 2O2 catalysts. Cu/Ce0. 8 Zr0. 2 O2 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 CuO was well dispersed on Ce0.8 Zr0.2 O2. 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 CuO dispersion and to reduce the competitive adsorption between CO and 02.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第7期1372-1377,共6页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:21273221)资助~~
