Co-Mo/Al_2O_3和Ru-Co-Mo/Al_2O_3催化剂的不同表面钴中心表征

A CHARACTERIZATION OF VARIOUS Co-SITES ON Co-Mo/Al_2O_3 AND Ru-Co-Mo/Al_2O_3 CATALYSTS

利用IR、MS方法对还原态的Co-Mo/Al_2O_3和Ru-Co-Mo/Al_2O_3催化剂进行了考察。结果表明,还原态的Co-Mo/Al_2O_3和Ru-Co-Mo/Al_2O_3表面上存在着不同的Co中心。可以十分明显地观察到,在Co-Mo/Al_2O_3上,NO吸附的红外光谱显示了1895和1880cm^(-1)谱带;在TPD-MS图上显示了353,423和473K谱峰。通过比较Co-Mo/Al_2O_3和Ru-Co-Mo/Al_2O_3,提出了在Ru-Co-Mo/Al_2O_3中Ru的加入主要是提高了NO在催化剂上的吸附速率和吸附量,增强吸附键的强度。

An investigation of the adsorption of NO on reduced Co-Mo/Al_2O_3 and Ru-Co-Mo/Al_2O_3 catalysts has been performed by using IR and MS spectros-copies, and it wasfound that two IR bands appeared at 1895 and 1880 cm^(-1) in the IR spectra and threepeaks exhibited at 353,423 and 473 K in the TPD-MS profiles. These are attributedto the various Co-sites on the surface of catalysts.Comparing Co-Mo/Al_2O_3 catalystwith Ru-Co-Mo/Al_2O_3 it was found that the addition of Ru in Ru-Co-Mo/Al_2O_3markedly led to an increase of the rate and amount for NO adsorption, which mayindicate that the HDS activity of Ru-Co-Mo/Al_2O_3 was much higher than that ofCo-Mo/Al_2O_3 catalyst.