CO2 hydrogenation to methanol promoted by intermetallic Ni5Ga3 and ZrO2 interface

Abstract

Intermetallic alloys have demonstrated significant potential for CO₂ hydrogenation to methanol; however, a comprehensive understanding of how the intermetallic-oxide interface regulates the catalytic performance remains elusive. Herein, we reported the influence of interface on the catalytic activity of intermetallic Ni₅Ga₃ supported on Al₂O₃ and ZrO₂. The Ni₅Ga₃/ZrO₂ interface promoted methanol formation rate by almost one order of magnitude in relation to bare Ni₅Ga₃. The in-situ spectroscopy combined with theory calculations revealed that the strong intermetallic-oxide interaction promoted the adsorption of H₂, facilitating the formation of active hydrogen species. Furthermore, CO₂ adsorption was enhanced due to the d-π hybridization between interface Ni sites and CO₂ molecules. The reaction predominantly followed the *HCOO pathway to form methanol over the Ni₅Ga₃/ZrO₂ interface, whereas *COOH on the bare intermetallic Ni₅Ga₃ led to undesired CO. Those findings highlight the critical role of intermetallic-oxides in modulating the reaction pathway in CO₂ hydrogenation to methanol.