The role of surface hydroxyl groups on a single-atomic Rh1/ZrO2 catalyst for direct methane oxidation†
A single atomic Rh catalyst immobilized on zirconia (Rh1/ZrO2) was modified by hydrothermal treatment to have surface hydroxyl groups and used for direct methane oxidation. Both O2 and H2O2 were used as oxidants. The amount of H2O2 could be reduced with enhanced methanol productivity in the presence of the surface hydroxyl groups. The formation of the surface hydroxyl groups upon hydrothermal treatment and their disappearance upon reaction were confirmed with diffuse reflectance infrared Fourier transform spectroscopy, indicating that the surface hydroxyl groups participate in the surface reaction.