Electron spin resonance study of SO2 and CO on CuO–alumina

Abstract

The intensity of the Cu2+ esr signal increased significantly on the addition of CO or SO2, especially with SO2, at room temperature to the preheated (at 400 °C) and evacuated CuO–alumina catalyst. When the CO or SO2 treated sample was evacuated at room temperature, the shape and intensity of the Cu2+ esr line returned to their original values. The intensity of the Cu2+ esr line decreased, but not to zero, on heating CuO–alumina either with CO or SO2. In the case of SO2, a new line appeared for the [Formula: see text] ion which was not affected on evacuation. It seems that the [Formula: see text] do not take part in the reduction of SO2 with CO over the CuO–alumina catalyst.