Malachite-Derived Inverse ZrO2/Cu Catalysts for Efficient CO2 Hydrogenation to Methanol

Abstract

Developing efficient catalysts for CO2 hydrogenation to methanol remains a challenge due to the inherent trade-off between activity, selectivity, and cost. Herein, a series of metal-promoted Cu catalysts (Zr, Zn, Ga) were synthesized via a ligand-modulated oxalate coprecipitation strategy using malachite-derived CuO as the precursor, enabling a low-cost and sustainable catalyst design. Among these, the ZrO2/Cu catalyst (Zr/Cu = 14:86) exhibits the optimal performance, delivering a CO2 conversion of 13% and a methanol space-time yield (STY) of 280.1 gMeOH·kgcat–1·h–1 at 280 °C and 3.0 MPa, together with excellent long-term stability. Characterization results suggest that highly dispersed Zr species effectively suppress Cu particle agglomeration while generating abundant surface oxygen vacancies (OV, 43.5%). Mechanistic studies indicate that Zr incorporation induces strong electronic metal–support interactions (EMSI), leading to the formation of electron-rich Cu0/Cu+ sites. These sites act cooperatively with OV, where the former facilitates H2 dissociation and the latter promotes CO2 adsorption and activation. Such synergistic effects favor the formate-mediated pathway while suppressing the competing reverse water–gas shift reaction. This work not only demonstrates a high-performance catalyst derived from natural minerals but also provides insights into the atomic-level synergy between electron-rich metal sites and surface defects, offering a viable strategy for the rational design of efficient catalysts for CO2 hydrogenation.