Mild-Condition Conversion of Methane to Acetic Acid over MoS2–Confined Rh–Fe Sites

The oriented conversion of CH4 to CH3COOH at low temperature, even room temperature, is both scientifically significant and industrially applicable for CH4 utilization, yet it is extremely challenging due to the difficulties associated with efficient CH4 activation and controllable C-C coupling. In this study, we for the first time achieve the room-temperature conversion of CH4 to CH3COOH using molecular O2 and CO over MoS2-confined Rh-Fe sites, which delivers an unprecedented CH3COOH selectivity of 90.3% and a productivity of 26.2 μmol gcat.-1 h-1 at 25 °C. Furthermore, the productivity of CH3COOH can be enhanced to 105.6 μmol gcat.-1 h-1 at 80 °C, while maintaining a high selectivity of 95.6%. Comprehensive experimental and theoretical investigation reveal the critical role of Rh-Fe synergy in the selective formation of CH3COOH. The confined Fe sites in MoS2 enable the activation of O2 to generate highly reactive Fe═O center for CH4 dissociation to CH3 species at room temperature, which then readily couple with adsorbed CO on adjacent Rh sites to form the key CH3CO intermediate for CH3COOH production. The unique structure of Rh-Fe sites offers synergistic catalytic properties that effectively balance C-H activation and C-C coupling, successfully addressing the trade-off between activity and selectivity in the carbonylation of CH4 to CH3COOH under mild conditions.