通过沉积沉淀法制备了Au负载量为3%的Au/CeO2催化剂,并利用表征手段结合固定床反应器试验研究了催化剂的理化特性和催化水煤气变换反应(water gas shift reaction,WGSR)的活性.结果表明:Au元素均匀地分散在了载体表面,改善了催化剂的氧...通过沉积沉淀法制备了Au负载量为3%的Au/CeO2催化剂,并利用表征手段结合固定床反应器试验研究了催化剂的理化特性和催化水煤气变换反应(water gas shift reaction,WGSR)的活性.结果表明:Au元素均匀地分散在了载体表面,改善了催化剂的氧化还原性能和CO吸附性能,进而提高了催化剂的活性,当反应温度为300℃时,WGSR试验中CO转化率提高了56.0%,O2促进了催化剂表面碳酸盐类物质的分解,恢复了催化剂的表面活性位,明显提高了低温下CO的转化率;当反应温度在200,250℃时,CO转化率分别提高了15.0%和17.5%.展开更多
The Cu-Mn catalysts doped with different amounts of lanthanum（La） for water-gas shift reaction（WGSR） were prepared, and characterized by X-ray diffraction（XRD）, temperature-programmed reduction（TPR）, temperatu...The Cu-Mn catalysts doped with different amounts of lanthanum（La） for water-gas shift reaction（WGSR） were prepared, and characterized by X-ray diffraction（XRD）, temperature-programmed reduction（TPR）, temperature-programmed reduction of oxidized surfaces（s-TPR）, temperature-programmed desorption of CO_2（CO_2-TPD）, infrared spectrum（FT-IR） and X-ray photoelectron spectroscopy（XPS）. Catalytic activities were tested for a water-gas shift reaction. The results showed that the introduction of 0.5 mol.% La could significantly improve the catalyst activity for low-temperature shift reaction compared with the undoped catalyst, which might be from the introduction of La making the Cu and Mn components distribute uniformly and the synergistic effect between Cu and Mn increasing the dispersion of Cu on the surface of the catalyst. The apparent CuO phases besides Cu_（1.5）Mn_（1.5）O_4 were found in the samples with at least 3.0 mol.% La content, and the basic sites increased with the increasing of La contents at a decreased rate. With excessive La doping, La particles would aggregate and cover some active sites, resulting in that Mn could not effectively inhibit the gathering together and growing up of Cu crystalline grain, and decreased the dispersion of Cu on the surface, which resulted in the poor activity of the catalyst for WGSR.展开更多
文摘通过沉积沉淀法制备了Au负载量为3%的Au/CeO2催化剂,并利用表征手段结合固定床反应器试验研究了催化剂的理化特性和催化水煤气变换反应(water gas shift reaction,WGSR)的活性.结果表明:Au元素均匀地分散在了载体表面,改善了催化剂的氧化还原性能和CO吸附性能,进而提高了催化剂的活性,当反应温度为300℃时,WGSR试验中CO转化率提高了56.0%,O2促进了催化剂表面碳酸盐类物质的分解,恢复了催化剂的表面活性位,明显提高了低温下CO的转化率;当反应温度在200,250℃时,CO转化率分别提高了15.0%和17.5%.
基金Project supported by the National Natural Science Foundation of China(21266017,21566028,21566029)Research Fund for the Doctoral Program of Higher Education of China(20111514110001)Inner Mongolia Natural Science Foundation(2014MS0220,2015BS0206)
文摘The Cu-Mn catalysts doped with different amounts of lanthanum（La） for water-gas shift reaction（WGSR） were prepared, and characterized by X-ray diffraction（XRD）, temperature-programmed reduction（TPR）, temperature-programmed reduction of oxidized surfaces（s-TPR）, temperature-programmed desorption of CO_2（CO_2-TPD）, infrared spectrum（FT-IR） and X-ray photoelectron spectroscopy（XPS）. Catalytic activities were tested for a water-gas shift reaction. The results showed that the introduction of 0.5 mol.% La could significantly improve the catalyst activity for low-temperature shift reaction compared with the undoped catalyst, which might be from the introduction of La making the Cu and Mn components distribute uniformly and the synergistic effect between Cu and Mn increasing the dispersion of Cu on the surface of the catalyst. The apparent CuO phases besides Cu_（1.5）Mn_（1.5）O_4 were found in the samples with at least 3.0 mol.% La content, and the basic sites increased with the increasing of La contents at a decreased rate. With excessive La doping, La particles would aggregate and cover some active sites, resulting in that Mn could not effectively inhibit the gathering together and growing up of Cu crystalline grain, and decreased the dispersion of Cu on the surface, which resulted in the poor activity of the catalyst for WGSR.
