Highly efficient hydrogenation of carbon dioxide to methyl formate over supported gold catalysts

Transformation of carbon dioxide (CO2) into valuable chemicals is an interesting topic in green chemistry. Hydrogenation of CO2 to methyl formate (MF) in the presence of methanol is an important reaction. In this work, Au nanocatalysts immobilized on different supports were prepared and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectrometry (XPS). The catalytic performances of the catalysts for the reaction were studied. It was demonstrated that the Au/ZrO2, Au/CeO2 and Au/TiO2 were very active and selective for the reaction in the absence of any basic additives. The Au/ZrO2 was more active than Au/CeO2 and Au/TiO2 if the sizes of Au particles on the supports were similar. Moreover, for the Au/ZrO2 catalysts, Au particles with smaller size had higher activity. The possible mechanism of the catalytic reaction was proposed.