Adjacent Metal Sites Steering Sequential C–H Activation and C–C Coupling for Efficient Methane Conversion to Ethanol

The selective oxidation of CH 4 to C 2 oxygenates under mild conditions is a significant pathway for CH 4 valorization, yet it remains extremely challenging due to the inertness of methane, the competing overoxidation, and sluggish C–C coupling kinetics. Here, we show that the N,S co-doped carbon nanotube-supported Fe 5 clusters catalyst (Fe 5 /NSC) with adjacent Fe sites drives sequential C–H activation and C–C coupling to ethanol with a C 2 H 5 OH productivity of 1939.6 μmol·g cat –1 ·h –1 and a selectivity of 83.9% at 25 °C and 0.5 MPa CH 4 without the assistance of CO. Comprehensive experimental investigation and density functional theory calculations reveal the critical role of adjacent Fe sites in the selective formation of C 2 H 5 OH. The adjacent Fe sites featured in Fe 5 /NSC synergistically facilitate the dissociation and/or partial oxidation of CH 4 to distinct C 1 intermediates (*OCH 2 and *CH 3 ) and subsequent OCH x –CH x coupling between them to form the key CH 3 CH 2 O* intermediate for C 2 H 5 OH production, as opposed to the conventional CH x –CO coupling pathway that primarily yields acetic acid.