CO 2 Hydrogenation to Methanol on ZnO/ZrO 2 Catalysts: Effects of Zirconia Phase

Abstract ZnO/ZrO 2 samples were obtained by impregnation ZnO on three different ZrO 2 polymorphic phases: monoclinic, tetrahedral and amorphous. The catalysts were tested for CO 2 hydrogenation to methanol and the structure was determined using nitrogen physisorption, scanning electron microscope (SEM), Fourier transform infrared (FT‐IR) pyridine adsorption, hydrogen temperature‐programmed desorption (H 2 ‐TPD), CO 2 ‐TPD and X‐ray photoelectron spectroscopy (XPS). The results showed that the ZnO/tm‐ZrO 2 ‐500 catalyst, with a mixture of both tetrahedral and monoclinic ZrO 2 phases, had the highest CH 3 OH yield among all the samples. The yield of methanol is correlated to the lattice oxygen content for all the catalysts. During the reaction, formate and methoxy species seemed to be the active intermediate species.