Synergistic interaction between Cu and ZrO2 promotes ethyl formate hydrogenation to produce methanol

Abstract

Converting formate to methanol is an economic strategy to expand the production of formate from CO2 electro-reduction while satisfying the increasing market demand for methanol. For selective hydrogenation of formate esters to methanol, it is crucial to understand how the interaction between metal catalyst and support affects catalytic performance. In this paper, ZrO2 was employed as the support to promote the Cu catalysts’ activity and selectivity in liquid-phase hydrogenation of ethyl formate. To maximize the production yield of methanol, various catalyst properties and reaction condition were investigated. Under the optimized conditions, i.e., 160 °C and 400 psi H2, ∼ 53 % of methanol were yielded from the hydrogenation of ethyl formate in anhydrous ethanol solvent over the 20 wt% Cu/ZrO2 catalyst. The calcination temperature in the catalyst synthesis had profound effects on the Cu valence states, the structure of the ZrO2 support, and the interactions between Cu and ZrO2. A variety of characterization tools, including XRD, XPS, and HRTEM, were used to elucidate the structure-activity relationship of the Cu/ZrO2 catalysts. These findings will facilitate the next-generation catalyst design and elucidate the synergistic interaction between Cu and ZrO2 that promotes ester hydrogenation reactions.