Pt/ZrO_2-Al_2O_3催化剂催化氧化C_3H_6和CO性能（英文）

Catalytic Oxidation of C_3H_6 and CO over Pt/ZrO_2-Al_2O_3 Catalyst

采用共沉淀法合成了ZrO_2与Al_2O_3的不同质量比的ZrO_2-Al_2O_3复合氧化物,并以此为载体通过等体积浸渍法制备了1.5%Pt/ZrO_2-Al_2O_3(w/w)催化剂。以C3H6和CO为反应物的催化性能评价显示,在系列催化剂中以Pt/Zr(0.4)-Al催化剂催化氧化活性最为优异,其C3H6和CO的起燃温度(T50)小于125℃,完全转化温度(T90)小于150℃。采用XRD、低温N2吸附、H2-TPR、CO脉冲吸附等分析表征技术探索了催化剂物相结构、比表面积、颗粒尺寸等对催化活性的影响规律。结果发现,ZrO_2-Al_2O_3复合氧化物具有Al_2O_3材料的介孔织构和大比表面积特性,且产生了AlxZr1-xOy固溶体新物相。适当的ZrO_2与Al_2O_3的质量比,是改善Pt与ZrO_2-Al_2O_3的相互作用强度,促进贵金属Pt的分散,提升Pt/ZrO_2-Al_2O_3催化剂的低温氧化活性的关键。

The ZrO2-A l2O3 composite oxides with different mass ratio of ZrO2 to A l2O3 were prepared by coprecipitation method.1.5%Pt/ZrO2-A l2O3(w/w)serial catalysts were prepared by isovolume impregnation method.The catalytic performance for C3H6 and CO oxidation show that Pt/Zr(0.4)-Al catalyst owns the most excellent catalytic activity.The temperature of light-off(T50)and the complete conversion temperature(T90)were less than 125 and 150"respectively.The effects of catalyst phase structure,specific surface area and particle size on the catalytic activity were investigated by XRD,N2 adsorption-desorption,H2-TPR and CO pulse adsorption.It is found that ZrO2-A l2O3 composite oxides have the mesoporous texture,large specific surface area,and a new phase of ALZri^Oy solid solution was also produced.The mass ratio of ZrO2 to A l2O3 is the key to improving the interaction between Pt and ZrO2-A l2O3,promoting the dispersion of Pt and enhancing the low temperature oxidation activity of Pt/ZrO2-A l2O3 catalyst