Bridged Ce3+-OH Species Boost Hydrogen Production in the Low-Temperature Methanol Steam Reforming Reaction

Abstract

Hydroxy groups derived from water dissociation play a crucial role in reforming chemistry. A direct experimental verification of interfacial hydroxy groups, however, together with the precise control of active -OH species for hydrogen production has not been obtained. This paper describes an interface engineering strategy to modulate active -OH species for hydrogen production from methanol steam reforming. Based on comprehensive in-situ spectroscopic characterizations, the normalized bridged Ce3+-OH species present linear correlation with the copper-ceria interface density, suggesting that bridged Ce3+-OH species are mainly adsorbed at the copper-ceria interface. The bridged Ce3+-OH species adsorbed at interfacial sites are demonstrated as 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 TOFH2 of approximately 956 h-1 at 220℃. This work provides a profound insight into the intrinsic reaction at the metal-support interfacial sites for the reforming chemistry.