Engineering Hydrogen Spillover via Zn Doping in Cu-ZnCeO _<i>z</i> Solid Solutions for Efficient Low-Temperature Methanol Synthesis

Selective hydrogenation of CO 2 to methanol at low temperatures is kinetically restricted by the scarcity of active hydrogen species on oxide surfaces. Herein, we constructed a series of Cu-supported ZnCeO z solid-solution catalysts and precisely tuned the hydrogen spillover capability by regulating the Zn doping level in the CeO 2 lattice, thereby achieving controllable activation of CO 2 and H 2 at low temperatures. The optimal Cu–Zn 3 Ce 2 O z catalyst achieved the CO 2 conversion of 9.2%, methanol selectivity of 98.1%, and methanol STY of 311.0 g·kg –1 ·h –1 at 200 °C. This enhanced performance stemmed from the substitution of Ce 4+ by Zn 2+ and the generation of abundant Zn–O v -Ce ensembles. These sites not only enhanced CO 2 adsorption but, more crucially, served as efficient reservoirs and activation sites for spillover-derived super hydrogen from metallic Cu. A strong dependence between the catalytic activity of CO 2 hydrogenation to methanol and the capability of hydrogen spillover was established, and the hydrogen spillover was suggested to be the key descriptor governing the reaction. High-pressure in situ DRIFTS experiments revealed that the spillover of active hydrogen species significantly promoted CO 3 2– conversion to HCOO – and the following hydrogenation of HCOO – to methanol. This work establishes the targeted engineering of hydrogen spillover as a robust strategy for the rational design of high-performance catalysts tailored for efficient low-temperature CO 2 utilization.