CAJ | 학술논문

采用浸渍法和沉积-沉淀法制备了CeO_2-Al_2O_3复合氧化物,比较了复合氧化物负载纳米金催化剂对水煤气变换反应的催化活性.通过N_2物理吸附、XRD、TEM、H_2-TPR等表征手段对复合氧化物及其负载金催化剂的物相和结构进行分析,发现复合氧化物的制备方法及其焙烧温度对其比表面积、孔结构及水煤气变换反应活性有明显的影响.与沉积-沉淀法相比,浸渍法制备的CeO_2-Al_2O_3复合氧化物具有较大的CeO_2晶粒尺寸,经500℃焙烧后再负载金,所得催化剂具有更高的活性,250℃时CO转化率可达78.1%.
채용침지법화침적-침정법제비료CeO_2-Al_2O_3복합양화물,비교료복합양화물부재납미금최화제대수매기변환반응적최화활성.통과N_2물리흡부、XRD、TEM、H_2-TPR등표정수단대복합양화물급기부재금최화제적물상화결구진행분석,발현복합양화물적제비방법급기배소온도대기비표면적、공결구급수매기변환반응활성유명현적영향.여침적-침정법상비,침지법제비적CeO_2-Al_2O_3복합양화물구유교대적CeO_2정립척촌,경500℃배소후재부재금,소득최화제구유경고적활성,250℃시CO전화솔가체78.1%.
Ceria-alumina composite oxides with different ceria loadings (5%, 10%, 20%, 25%, and 30%) were prepared by impregnation method and deposition-precipitation method, respectively. Gold catalysts supported on these oxides were used to water gas shift reaction. All samples were characterized by nitrogen adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) and hydrogen temperature-programmed reduction (H_2-TPR). It is found that the preparation method and calcination temperature of ceria-alumina oxides have a marked influence on their surface areas, porous structures and the catalytic performances of supported gold catalysts for water gas shift reaction. Ceria-alumina oxides prepared with impregnation method gave larger ceria particle size and high catalytic activity than those prepared with deposition-precipitation method. Gold catalyst supported on 20%CeO_2-Al_2O_3 oxide calcined at 500℃ showed the highest activity. CO conversion reached 78.1% at 250℃ and atmospheric pressure.