Single-atom Fe with Fe-N4F1 structure showing superior performances for semi-hydrogenation of alkynol

The design of non-noble metal single-atom catalysts (SACs) with superior performance for semi-hydrogenation of alkynol to alkenol is remarkable but challenging. Herein, fluorine-tuned Fe SACs supported on N, F-codoped carbon (Fe 1 -NFC) with a Fe-N 4 F 1 structure is successfully prepared via a complexation method. The axial F-doping can modulate the electronic structure of the metalloporphyrin-like active sites (Fe-N 4 ), promoting the transfer of electrons from Fe atoms to F atoms to form electron-deficient Fe δ+ species. As a result, the Fe 1 -NFC catalyst shows a remarkable activity for the semi-hydrogenation of 2-methyl-3-butyn-2-ol to 2-methyl-3-buten-2-ol under mild conditions, with a TOF of 9163 h −1 and a selectivity of 96 % at 97 % conversion, both much higher than that of the Fe SACs supported on N-doped carbon (Fe 1 -NC). Density functional theory (DFT) calculations reveal that the excellent catalytic activity is attributed to the interfacial electronic effect of Fe species induced by axial F-doping, thereby enhancing the exothermic adsorption of alkynol on the Fe-N 4 F 1 structures and accelerating the desorption of alkenol to against the overhydrogenation.