利用CO和NO探针分子的红外光谱研究钴和钌的助剂作用

STUDY ON THE PROMOTION EFFECTS OF COBALT AND RUTHENIUM BY IR-SPECTOSCOPY OF CO AND NO COADSORPTION

本文采用CO、NO作为分子探针,应用红外光谱方法研究了钻和钌在加氢脱硫(HDS)催化剂中修饰钼中心的助剂作用。由实验结果发现,钻使钼中心吸附的NO量减少,而钌则使钼中心吸附的NO量增加。实验结果表明,钴担载在MoS_2的边角位置,与钼中心发生化学作用形成CoMoS相,这种COMoS相对CO和NO有吸附活性。而钌的作用则是促进氢的解离,进而这些解离氢溢流到MoS_2上发生还原反应,生成更多的配位不饱和钼中心。

Infrared spectroscopy with CO and NO as probe molectlles has been used to elucidate the functions of cobalt and ruthenium in sulfided Co-MO/Al_2O_3,Ru-Mo/Al_2O_3,and Ru-Co-Mo/Al_2O_3 catalysts.It is found that cobalt partially blocks Mo sites and decreases NO chemisorption.In contrast to Cobalt,the addition of ruthenium to Mo/Al_2O_3 and Co-Mo/Al_2O_3 catalysts increases the adsorption of CO and NO on coordinatively unsaturated Mo sites.Cobalt is located on Mo edge sites to form a CoMoS phase,whereas ruthenium enhances the dissociation of hy drogeil and the active hydrogen spills over oil to Mo sites to promote its reduction.