Site-selective ethanol conversion over supported copper catalysts

► Different than for Cu/ZrO2, over Cu/SiO2, Cu1+ was prevalent over Cu0 species. ► Cu1+/Cu0 and Cu0 interfaced to ZrO2 are needed to higher selectivity to ethyl acetate. ► Cu1+/Cu0 pair provided by Cu/SiO2 generates sites highly selective to acetaldehyde.