Cu/Zn-ZIF-8 derived yolk–shell ZnO supported Cu nanoparticles for mild hydrogenation of CO₂ to methanol

Cu/ZnO catalyst has been widely studied for selective hydrogenation of greenhouse gas CO₂ to value-added methanol but it remains challenging for obtaining methanol under mild condition. Here we show utilizing the typical bimetallic zeolitic imidazolate framework-8 (known as Cu/Zn-ZIF-8) as precursors to construct polycrystalline yolk–shell typed ZnO (p-ZnO_yk) supported Cu nanoparticles, denoted as Cu/p-ZnO_yk, for selective hydrogenation of CO₂ to methanol. This catalyst exhibits 98.5% selectivity of methanol and its production rate up to 15.8 mg·h⁻¹·g_cat⁻¹ at a CO₂ conversion ratio of 1.5% under 180 °C and 3 MPa CO₂/H₂ (1/3) as well as long-term stability for 500 h reaction on stream, superior to the reported Cu based catalysts under mild condition. Various spectroscopic analyses reveal that this yolk–shell structured catalyst exhibits strong interfacial electron transfer from Cu nanoparticles to p-ZnO_yk in Cu/p-ZnO_yk, which generates Cu⁺ active sites, facilitating the adsorption and activation of CO₂ at the interface and enhancing methanol production via formate pathway. This work provides a strategy for constructing novel structured Cu-ZnO hybrid catalyst with strong interfacial electron effect for significantly boosting CO₂ hydrogenation to produce methanol.