Preparation of Pt/MoO3_/ZrO_2 Catalyst and its Property of Three-Way Catalysts

MoO_3/ZrO_2 was prepared by impregnation method.Its specific surface area,pore size, pore volume and surface acidity were investigated by means of low temperature nitrogen adsorption- desorption and NH_3-temperature programmed desorption.By using MoO_3/ZrO_2 and La_2O_3/Al_2O_3 as catalyst support,Pt/MoO_3/ZrO_2 and Pt/La_2O_3/Al_2O_3 catalysts were prepared by wet impregnation method and the activity test of C_3H_8,CO,NO were also investigated in the simulated automotive gas. The results show that MoO_3/ZrO_2 has good texture(S_(BET)=106.8m~2/g)and surface super-acidity.And the catalysts were also characterized by X-ray diffraction and H_2-temperature programmed reduction. Compared with traditional three-way catalyst Pt/La_2O_3/Al_2O_3,Pt/MoO_3/ZrO_2 exhibits lower light-off temperature of hydrocarbon(230℃),carbon monoxide(200℃),and nitrogen oxides(210℃)and wider operational air-to-fuel ratio window,which especially improves C_3H_8 conversion under higher oxidative conditions.The results also show that Pt on the catalyst support has high dispersion and excellent redox properties.