采用浸渍法制备了MoO3/ZrO2,用低温氮吸附-脱附法和NH3-程序升温脱附法(TPD)分别对其比表面积和酸碱性进行了表征.结果表明,MoO3/ZrO2具有106.8m~2/g的比表面积和超强酸的性能.用等体积浸渍法制备了Pt/MoO3/ZrO2催化剂,在汽车尾气模拟气中考察了其对C3H8、CO和NO的催化活性.与传统三效催化剂Pt/La2O3/Al2O3相比较,Pt/MoO3/ZrO2具有更好的低温起燃性能和更宽的空燃比窗口,并显著地改善了C3H8在富氧状态下的转化效率.通过XRD、H2-TPR对催化剂进行了表征,结果表明,Pt在催化剂载体上具有高度的分散性和优异的氧化还原性能.
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)=106.8m2/g)and surface super-acidity.And the catalysts were also characterized by X-ray diffraction and H2-temperature programmed reduction. Compared with traditional three-way catalyst Pt/La2O3/Al2O3,Pt/MoO3/ZrO2 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 C3H8 conversion under higher oxidative conditions.The results also show that Pt on the catalyst support has high dispersion and excellent redox properties.