Interfacial-Confined Oxygen Vacancy Clusters in ZrO-Supported InO Catalysts Boost Methanol Production From CO.

Oxygen vacancies (V) play a vital role in catalytic reactions. Tuning the V structures beyond its density is of great significance for optimizing catalytic performance, but remains challenging due to uncontrolled reduction and its poor stability under reaction conditions. Here, we report that the integration of quantum size effect for enhanced InO reducibility with strong In-O-Zr interfacial confinement for high stability enables the creation of stable large-size V clusters (e.g., trimers, tetramers, and larger) on ZrO-supported monolayer InO nano-islands with high density without overreduction to metallic indium. In the CO hydrogenation reaction, the ZrO-supported monolayer InO catalyst with V clusters exhibits a considerably higher intrinsic activity for methanol production than that of bulk InO with single V sites. Further addition of Pd onto these monolayer InO with enriched V clusters allows achieving an unprecedentedly high methanol space-time yield of 46.6 mmol·g  h at 270 °C along with long-term stability for at least 200 h, surpassing all InO-based catalysts reported to date.