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106.8m2/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(SBET=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.
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