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

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.