Fine-tuning the electronic properties of Au toward two-dimensional clusters with higher activity for ethanol conversion

Efficient Au/m-ZrO2 catalysts for the conversion of ethanol to acetaldehyde and ethyl acetate were obtained by the deposition precipitation method. The present work investigates the impact of the electronic properties of Au supports on m-ZrO2 catalysts on ethanol dehydrogenation. The Au4f7/2 binding energy (BE) and the average Au-Au nearest-neighbor distances (RAu-Au) were associated with surface defects characterized by CO adsorption. The BE and RAu-Au properties are correlated among themselves, changing by Au loading and pretreatments in an inert atmosphere at different temperatures. Although the RAu-Au unveils a boost of the reaction rates for shorter distances, the coupling of Au and m-ZrO2 produced a bifunctional catalyst. Theoretical studies indicate that molecular ethanol adsorption and formation of the ethoxy intermediate represented a feasible pathway for the activation of ethanol on the Au-ZrO2 interface. The RAu-Au toward of 2D clusters conferred high catalytic activity and low apparent activation energy for ethanol dehydrogenation.