Impact of the copper load on the performance of Cu/UiO-67 in CO2 hydrogenation to ethanol at atmospheric pressure

Abstract

CO2 hydrogenation to ethanol could be a potential approach to reduce dependence on fossil resources, but faces challenges related to product selectivity and catalyst stability. MOFs, particularly UiO-67, acting as a support for copper catalysts can contribute to overcoming these limitations by stabilizing intermediates, creating interfaces that protect active sites against deactivation and potentially generating synergistic effects that favor the formation of the C-C bond. In this scenario, the present work aims to synthesize Cu/UiO-67 for application in the CO2 hydrogenation to ethanol at atmospheric pressure. The impact of the copper loading (5–60 wt%) on the catalyst physical properties and ethanol productivity was evaluated. Using XRD, N2 physisorption, TEM-EDS, FTIR and H2-TPR, it was possible to confirm the maintenance of the UiO-67 structure, which begins to deform with increasing copper content. Catalytic results showed that ethanol, methanol, propanol, carbon monoxide, and acetaldehyde have been produced. The selectivity of alcohols is related to the amount of copper, decreasing at high contents, indicating the importance of active sites interaction with SBUs units in alcohols formations.