文献类型：期刊文献

英文题名：Effect of water on the performance of Pd-ZSM-5 catalysts for the combustion of methane

作者：Zhang, Bo[1];Wang, Xingyi[1];M'Ramadj, Ogtour[1];Li, Dao[1];Zhang, Hua[1];Lu, Guanzhong[1]

机构：[1]E China Univ Sci & Technol, Res Inst Ind Catalysis, Adv Mat Lab, Shanghai 200237, Peoples R China

年份：2008

卷号：17

期号：1

起止页码：87

外文期刊名：JOURNAL OF NATURAL GAS CHEMISTRY

收录：;EI(收录号：20081911239966);WOS:【SCI-EXPANDED(收录号:WOS:000255491700014)】；

语种：英文

外文关键词：methane combustion; Bronsted acid; palladium; ZSM-5; water

摘要：Palladium-based catalysts were prepared using impregnation (1) and ion-exchange method (E) with ZSM-5 as support. Pd-ZSM-5(I) and Pd-ZSM-5(E) catalysts presented the high activity for the combustion of methane. The order of activity was consistent with Bronsted acidity of the catalysts: Pd-ZSM-5(I)>Pd-ZSM-5(E). It was shown by FT-IR that methane was adsorbed on the acidic bridging hydroxyl groups of ZSM-5-supported Pd catalysts. The effect of water on the activity of Pd-ZSM-5 was investigated. The inhibition effect of water on the conversion of methane was observed. However, water promoted the stability of Pd-ZSM-5 obviously during extended time periods. XPS measurement showed that Pd/Si ratio near the surface of Pd-ZSM-5(E) decreased more pronouncedly with time in dry stream than that of Pd-ZSM-5(I), this is attributed to the dispersion of Pd into the micropores. The addition of water, however, retarded Pd dispersion. And high partial pressure of methane reduced this effect of water vapor. The decrease in activity during the stability test can be explained on the basis of the reduction of Pd/Si ratio.