催化碳烟氧化用PtCexZr1-xO2催化剂的制备及性能研究

采用水热晶化法一步制备了铈锆摩尔比不同的PtCe_xZr_(1-x)O_2系列催化剂,测定其比表面积、储氧量、氢气还原温度等物化性能参数,并进行结构表征,研究催化剂组成中铈锆摩尔比(n_(Ce)/n_(Zr))对催化剂结构和性能的影响。结果表明,当n_(Ce)/n_(Zr)=5:5时,制备得到的PtCe_(0.5)Zr_(0.5)O_2催化剂晶粒尺寸最小,储氧量较高,氢气还原温度低,微观结构为四方相和立方相2种晶型结构并存的固溶体。与传统贵金属浸渍负载方法制备的Pt/Ce_(0.5)Zr_(0.5)O_2催化剂相比较,水热晶化法一步制备的PtCe_(0.5)Zr_(0.5)O_2催化剂对碳烟的低温氧化具有更优的催化活性。

Study on preparation and performance of PtCexZr1-xO2 catalysts for soot oxidation

A series ofPtCexZr1-xO2 catalysts were prepared by one-step hydrothermal crystallization method. The influences of the molar rate of Ce and Zr (nCe/nZr) on physical and chemical properties of the catalysts were investigated by specific surface area, oxygen storage capacity, reduction temperature test and X-ray diffractometer methods. The results showed that the catalyst with a ratio of nCe/nZr=5:5 had the smallest grain size, higher oxygen storage capacity, lower reduction temperature, and that the microstructure was solid solution nanoparticles with tetragonal and cubic phases. Compared with the Pt/Ce0.5Zr0.5O2 catalyst prepared by a traditional method, the PtCe0.5Zr0.5O2 catalyst prepared by one-step hydrothermal crystallization method had better catalytic activity for soot low-temperature oxidation.