Migration and reduction of formate to form methanol on Cu/ZnO catalysts

Temperature-programmed decomposition (TPD) and temperature-programmed hydrogenation (TPH) experiments were performed on copper and zinc formates. Formic acid was found to be the only organic product from the copper formate reactions. Methanol and methyl formate were found to be the major organic products from the zinc formate reactions, When ZnO was mixed with copper formate, the yields of methanol and methyl formate increased. Temperature-programmed IR (TPIR) spectroscopy of the copper formate/ZnO indicated the migration of the formate from copper to ZnO in the temperature range below 430 K at which the decomposition of the copper formate began, The experimental results elucidated the synergistic effect between copper and ZnO; formate migration onto ZnO and its hydrogenation to methanol on ZnO, Based on the synergistic effect, a reaction mechanism for methanol synthesis from the hydrogenation of carbon oxides in Cu/ZnO catalysts was proposed.