Electronic Metal–Support Interaction at ZnO _<i>x</i> /Cu Interface Enhances H ₂ Production in Methanol Steam Reforming

Methanol steam reforming (MSR) is a promising technology for in situ hydrogen production, while the mechanistic role of zinc in the widely used Cu/ZnO/Al₂O₃ catalyst remains ambiguous. Electronic metal-support interactions (EMSIs) are generally applied for modulating active sites in such heterogeneous catalysts, offering opportunities to optimize energy conversion processes. Here, we revealed that a dynamic EMSI between Cu and ZnO enhances catalytic performance by constructing ZnO_<i>x</i>/Cu interfaces, facilitating bidirectional electron transfer between ZnO_<i>x</i> and Cu. The electron transfer from ZnO_<i>x</i> to Cu mitigates overoxidation of Cu⁰ to Cu⁺ during water activation, thereby improving water activation efficiency, while the electron transfer back to ZnO_<i>x</i> accelerates the reduction of Cu⁺ back to Cu⁰, promoting dehydrogenation of reactive formate at the ZnO_<i>x</i>/Cu interface, the rate-determining step at low temperatures. Thus, we establish a dual role for the EMSI-induced ZnO_<i>x</i>/Cu interface in stabilizing active intermediates and facilitating redox cycling. These findings provide insights into the precise regulation of catalytic active sites via EMSI engineering, offering guidance for high-efficiency catalysts design for sustainable energy conversion.