助剂对低温水煤气变换反应Au/αFe2O3催化剂性能的影响

The Au/αFe2O3MOxcatalysts(M=Zr、Al、Mg、Ca、Ba) prepared by coprecipitation method were characterized by BET ,XRD, H2-TPR and CO2-TPD-MS.The catalytic performance for lowtemperature watergas shift reaction(WGSR) in H2 rich gas was investigated. It was found that the activity and stability of Au/αFe2O3MOxwas strongly dependent on the type of additive. Among the tested samples, the Au/αFe2O3 catalyst modified by ZrO2 or Al2O3 showed highest activity and stability. On the contrary, the modification by MgO,CaO and BaO resulted in an activity decrease. The structure and surface analyses revealed that zirconia added to the the Au/αFe2O3 catalyst increased the surface area, decreased crystallite size of support, and limited the growth of the crystallite size of support during the catalytic reaction. The results indicated that addition of the promoter zirconia and alumina, changed the structure and performances of the support and resulted in higher activity and stability.