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 g_cat.^-1 h^-1 at 25 °C. Furthermore, the productivity of CH₃COOH can be enhanced to 105.6 μmol g_cat.^-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.