Microkinetic analysis of isopropanol dehydrogenation over Cu/SiO2 catalyst Original Research Article

The reaction of isopropanol dehydrogenation to acetone over the Cu/SiO2 catalyst was studied using the method of microkinetic analysis. This analysis provided a picture about the coverage of different surface species and their influences on the reaction rate. Specifically, the analysis reinforced the previously proposed mechanism and added some new findings for the reaction. It was found that under the normal reaction conditions, the catalyst surface is mostly covered by the isopropoxyl groups and the overall reaction rate is controlled by the elimination of α-H of the isopropoxyl groups. In addition, the elimination of the α-H is significantly affected by the availability of surface Cu sites. At the low hydrogen partial pressure, the number of bare surface Cu sites increases with the increasing of hydrogen partial pressure, leading to the increased overall reaction rate and thus the positive reaction order with respect to hydrogen. Thus, hydrogen can enhance the rate of this reaction via some kinetic factors under the specific coverage regime, although it is thermodynamically unfavorable for the reaction.