This paper reports the fabrication of a single-atom iron catalyst by saturated adsorption of trace iron onto zeolitic imidazolate framework-8 (ZIF-8) followed by pyrolysis. The catalyst exhibits exceptional performance in catalytic transfer hydrogenation of furfural, rivaling state-of-the-art catalysts and exceeding others by up to four orders of magnitude. Mechanistic studies, including isotopic labeling and first-principles simulations, reveal pyrrolic Fe(II)-PIN3 as the active center, highlighting the crucial role of structural flexibility in facilitating the reaction. The catalyst demonstrates chemoselectivity and a unique dependence on substrate acidity.

Zhidong An, Piaoping Yang, Delong Duan, Jiang Li, Tong Wan, Yue Kong, Stavros Caratzoulas, Shuting Xiang, Jiaxing Liu, Lei Huang, Anatoly I. Frenkel, Yuan-Ye Jiang, Ran Long, Zhenxing Li, Dionisios G. Vlachos