Bridged Ce3+–OH species boost hydrogen production in the low-temperature methanol steam reforming reaction

Abstract

Hydroxyl groups derived from water dissociation play a crucial role in reforming chemistry. Direct spectroscopic verification of interfacial hydroxyl groups, however, together with the precise control of active –OH species for hydrogen production, has not been obtained. This paper describes an interfacial engineering strategy to modulate active –OH species for hydrogen production from methanol steam reforming. Based on comprehensive in situ spectroscopic characterizations, normalized bridged Ce³⁺–OH species present a linear correlation with the copper–ceria interface density, suggesting that bridged Ce³⁺–OH species are mainly adsorbed at the copper–ceria interface. We demonstrated that the bridged Ce³⁺–OH species adsorbed at interfacial sites are the primary active configurations that react with methoxy groups to generate formate species, thereby enhancing hydrogen production in low-temperature methanol steam reforming, achieving an optimal TOF_H2 of approximately 956 h⁻¹ at 220 °C. This work provides profound insight into the intrinsic reaction at metal–support interfacial sites for reforming chemistry.