Surface Oxygen Revealed by CO Oxidation and EMF Measurements over Several Supported Rh-Catalysts and Its Contribution to Catalytic Activity

Abstract

Mechanism of CO oxidation over Rh/metal oxide catalysts (Rh/VO^2-, Rh/UO₂, Rh/WO^2-, Rh/ MgWO₄, and Rh/CaWO₄) was studied by means of a pulse reaction method combined with an electromotive force (EMF) measurement.
The activity of each catalyst was propotional to the amount of surface oxygen, but its propotionality constant was different from each other. Its propotionality constant was correlated to EMF change a(4E)10x, related to the removal of oxygen from the catalyst by CO pulse. Furthermore, a(zIE)16x value was correlated to the oxidation activity of the catalyst for CO pulse reaction.
This fact suggested that 8(4E)18x value related to the oxidation ability of the catalyst and would be used for convenience as a measure of its ability.