载体焙烧温度对CuO/CeO_2-MnO_x催化剂富氢条件下CO氧化性能的影响

Effect of CeO_2-MnO_x calcination temperature on preferential oxidation of CO in H_2-rich gases over CuO based catalysts

以共沉淀法制备了CeO2-MnOx复合金属氧化物,考察了其焙烧温度对Cu/CeO2-MnOx催化剂富氢条件下CO氧化性能的影响,并运用XRD、BET、TPR和TPD等手段对样品进行了表征。结果表明,载体的焙烧温度对CuO/CeO2-MnOx催化剂的结构性质、还原性能及催化活性有一定的影响。当CeO2-MnOx500℃焙烧时,CuO/CeO2-MOx催化剂表现出最好的活性,与CeO2-MnOx部分固溶体的形成、CeO2与MnOx之间较强的相互作用、其表面较大量的高分散CuxO物种及较大的CO吸附量有关。

The coprecipitation method was applied to prepare CeOx-MnOx composite metal oxide. The effect of CeOx-MnOx calcination temperature on CO preferential oxidation in H2-rich gases over CuO based catalyst was investigated. The samples were characterized by means of X-ray diffraction （XRD）,BET surface area, H2 temperature-programmed reduction （H2-TPR）, CO temperature-programmed desorption （CO- TPD） and X-ray photoelectron spectra （XPS）. Results showed that the calcination temperature of CeO2- MnOx supports would have certain impact on the structural properties, redox performance and catalytical activities of CuO/CeOx-MnOx catalysts for the CO preferential oxidation in H2-rich gases. When calcined at 500℃ ,CuO/CeOx-MnOx catalyst exhibited the best catalytic activity and higher CO conversion in H2-rich gas,which should be related to the partly formation of CeOx-MnOx solid solution, stronger interaction between the CeOx and MnOx ,more amounts of highly dispersed CuxO and more CO adsorption amounts.