钴基费-托合成催化剂上CO、H_2的吸附行为

采用程序升温脱附及FT-IR技术考察了CO、H2在钴基催化剂上的吸附行为.H2-TPD表明,Co/SiO2催化剂有两类脱附氢,引入锆助剂后,低温脱附氢量明显增加,高温吸附氢量下降.CO-TPD及吸附态CO的红外光谱表明锆助剂使CO在钴催化剂上的吸附强度减弱,但其吸附量增大.钴基催化剂的费-托合成反应性能可以用吸附态物种的变化来解释.

H_2 or CO Chemsorption on Co-based Catalysts for F-T Synthesis

Both Co/SiO2 and Co/ZrO2/SiO2 catalysts for F-T synthesis were characterized by temperature programmed desorption (TPD) and FT-IR spectra.H2-TPD evidenced that there were two H2 desorption peaks over Co/SiO2 catalyst and that the amount of H2 adsorption decreased upon introduction of ZrO2.CO-TPD and CO-IR showed that addition of ZrO2 weakened the intensity of CO adsorption but increased the amount of adsorbed CO.In F-T synthesis,ZrO2 promoter enhanced the formation of heavy hydrocarbons in addition to keeping high activity.Such a shift of product array to heavier hydrocarbon was related to the increase of surface H2/CO ratio.