摘要
本文和ＴＰＲ，ＩＲ，ＴＰＤ和ＴＰＳＲ等技术研究了以表面改性法制备的Ｍｇｏ－ＳｉＯ（ＭＳＯ）表面复合物担载的Ｎｉ－Ｃｕ合金间的相互作用及其对ＣＯ加氢反应催化性能影响。
Interaction and catalytic behavior of Ni-Cu/MgO-SiO2(MSO)catalyst have been investigated by using TPR, IR, TPD-MS and TPSRMS. The MSO complex oxide suppport was prepared by modifying thesurface character. In process of preparing the catalyst, a particle of NiOreacts with MgO to form surface species Ni2+ -O-Mg2+ with theresult that increases remarkably the reduction temperature of NiO. Onthe surface of reduced Ni-Cu/MSO catalyst, there are two types of active sites, Ni in Ni-Cu alloy and Mg2+ in MSO support. With their cooperation, four types of CO adsorption, twin Ni - (CO )2, linearNi-CO, bridge Ni2 -CO and horizontal Ni...C= O→Mg2+, have beenfound on the catalyst, and the horizontal one collapses easily to formNi-C and Mg2+ -O. H2 dissociative adsorption on the catalyst takesplace as H2 +Ni + (Mg2+ -O)→ (Ni - H) + (Mg+ - OH). The surface Ni-C leads to CO hydrogenation on Ni sites along carbide mechanism. The Mg2+-OH leads to the formation of H2O on Mg2+ sites. OnNi-Cu/MSO catalyst, CO conversion is more than 70%, and C2H4 selectivity is over 80%.
关键词
氧化镁
氧化硅
镍
铜
金属催化剂
一氧化碳
加氢
titania-silica surface complex, nickel-copper bimetallic catalyst, metal support interaction, carbon monoxide,hydrogenation
