Preparation of Pt/MoO₃/ZrO₂ Catalyst and its Property of Three-Way Catalysts: Preparation of Pt/MoO₃/ZrO₂ Catalyst and its Property of Three-Way Catalysts

MoO3/ZrO2 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 NH3-temperature programmed desorption. By using MoO3/ZrO2 and La2O3/Al2O3 as catalyst support, Pt/MoO3/ZrO2 and Pt/La2O3/Al2O3 catalysts were prepared by wet impregnation method and the activity test of C3H8, CO, NO were also investigated in the simulated automotive gas. The results show that MoO3/ZrO2 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/La2O3/Al2O3, Pt/MoO3/ZrO2 exhibits lower light-off temperature of hydrocarbon (230 degrees C), carbon monoxide (200 degrees C), and nitrogen oxides (210 degrees C) and wider operational air-to-fuel ratio window, which especially improves C3H8 conversion under higher oxidative conditons. The results also show that Pt on the catalyst support has high dispersion and excellent redox properties.