Dehydrogenation of isopropanol on a modified copper catalyst

Abstract

The influence of plasmochemical treatments of the 5 wt % Cu/SiO2 catalyst and cerium additives on the activity of the catalyst in isopropanol dehydrogenation was studied. After the catalyst was treated with high-frequency plasma in H2 under the flow conditions, the conversion of alcohol increased. The reaction kinetics was studied under static conditions. The rate constant increased 1430-fold after the introduction of an optimum dose of Ce and treatment in Ar, O2, and H2 plasma and 550-fold after treatment with high-frequency plasma in H2. The experimental activation energy increased in all instances; the activity grew because of the increase in the number of active centers. The promoting action of cerium was explained by the positive charge of the Ce+α adatom, which initiated growth of the surface electron density; the influence of plasmochemical treatments was explained by the change in the number of structural defects and their character. Possible stepwise reaction schemes were considered based on ab initio quantum-chemical calculations.