Abstract: The effects of CrAl carrier preparation process and Pd loading methods on the catalytic activity of Cr modified Pd/Al2O3 catalyst for low concentration methane combustion were investigated，and the influence of Ce addition on the high-temperature stability of catalyst was also tested. X-ray diffraction and temperature programmed reduction were used to characterize the structure and redox ability of catalysts. The I-CrAl carrier prepared by impregnation had high specific surface area，and the pores were not blocked. Reduction treatment in the process of Pd loading significantly improved the activity of catalysts. Temperature-programmed reduction with hydrogen verified that the reduction process improved the catalyst reduction ability. Addition of Ce enhanced catalyst stability by resisting sintering of Al2O3 at high temperature.

Key words: palladium-based catalysts, catalyst support, oxidation, catalysis, Cr promoted, stability

摘要： 研究了Cr改性Pd/Al2O3催化剂上低浓度甲烷的催化燃烧反应，考察了载体CrAl的制备方法和活性组分Pd的负载方法对催化剂催化活性的影响以及添加Ce对催化剂高温稳定性的影响。采用X射线衍射、程序升温还原等表征手段分析了催化剂结构和氧化还原性。结果表明，与采用沉淀法制备的载体P-CrAl相比，采用浸渍法制备的载体I-CrAl具有较高的比表面积和反应活性；用NaBH3对Pd负载过程进行还原处理能明显提高催化剂活性，其原因是还原过程加强了催化剂上Pd与载体CrAl之间的作用，通过H2-TPR证明了其还原能力得到了增加；添加Ce缓解了Al2O3高温条件下的烧结，增强了催化剂的高温稳定性。

关键词: Pd基催化剂, 催化剂载体, 氧化, 催化（作用）, Cr改性, 稳定性