Yang, Bing; Yu, Xin; Halder, Avik; Zhang, Xiaoben; Zhou, Xiong; Mannie, J.; Tyo, Eric; Pellin, Michael; Seifert, Soenke; Su, Dangsheng; Vajda, Stefan
Atomically precise subnanometer catalysts are of significant interest because of their remarkable efficiency in a variety of catalytic reactions. However, the dynamic changes of active sites under reaction conditions, in particular, the transition of cluster-oxide interface structure have not yet been well-elucidated, lacking in situ measurements. By using multiple state-of-the-art in situ characterizations, here we show a dynamic interplay between copper tetramers and iron oxides in a single-size Cu-4/Fe2O3 catalyst, yielding an enrichment of surface Cu-4-Fe2+ species under reaction conditions that boosts CO2 hydrogenation at near-atmospheric pressures. During reaction, Cu-4 clusters facilitate the reduction of Fe2O3 producing surface-rich Fe2+ species in the proximate sites. The as-formed Fe2+ species in return promotes CO2 activation and transformation over Cu4 cluster, resulting in strikingly high methanol synthesis at low temperatures and C-1/C-3 hydrocarbon production in a high-temperature régime. The discovery of highly active Cu-4-Fe2+ sites thus provides new insights for the atomic-level design of copper catalyst toward high-efficiency CO2 conversion under mild conditions.