CeO2修饰的Pt／SiC催化剂催化CO氧化反应的性能

Effect of Addition of Promoter CeO_2 in Pt/SiC Catalyst on CO Oxidation

以SiC为载体,采用等体积浸渍法制备了Pt质量分数为1%的Pt/CeO2/SiC催化剂,采用X射线衍射、程序升温还原和CO化学吸附法对催化剂进行了表征。考察了CeO2添加量、焙烧温度、预还原温度等对Pt/CeO2/SiC催化剂催化CO氧化反应性能的影响。实验结果表明,添加助剂CeO2可显著提高催化剂表面活性组分Pt的分散度,且CeO2与Pt产生一定的相互作用,使催化剂活性显著提高;当Pt/CeO2/SiC催化剂中CeO2的质量分数为8%时,催化剂活性最高,CO的最低完全转化温度比Pt/SiC催化剂约低100℃;Pt/CeO2/SiC催化剂的最佳焙烧温度为500℃,最佳预还原温度为200℃。

A series of Pt/CeO2/SiC catalysts were prepared by impregnation with SiC as support and CeO2 as promoter, and were used in CO oxidation. The catalysts were characterized by means of XRD, H2 temperature programmed reduction and CO chemical adsorption. Effects of CeO2 loading amount, calcination temperature and pre-reduction temperature on catalytic properties of the catalysts were investigated. Addition of CeO2 enhances Pt dispersity on surface of support and interaction between Pt and CeO2 ,SO improves activity of catalyst in oxidation of CO. The catalyst with 8% （mass fraction）of CeO2 exhibits the highest catalytic activity. Comparing-with Pt/SiC catalyst without CeO2, the lowest complete conversion temperature of CO reduces by 100 ℃. The optimal calcination temperature and pre-reduction temperature of the catalyst are 500 ℃ and 200 ℃, respectively.