Mild-Condition Conversion of Methane to Acetic Acid over MoS<sub>2</sub>–Confined Rh–Fe Sites
Jun Mao, Huan Liu, Yanan Li, Meng Gao, Yunlong Zhang, Yao Song, Mo Zhang, Guilan Xu, Wu Zhou, Liang Yu, Xiaoju Cui, Dehui Deng
Abstract
The oriented conversion of CH 4 to CH 3 COOH at low temperature, even room temperature, is both scientifically significant and industrially applicable for CH 4 utilization, yet it is extremely challenging due to the difficulties associated with efficient CH 4 activation and controllable C–C coupling. In this study, we for the first time achieve the room-temperature conversion of CH 4 to CH 3 COOH using molecular O 2 and CO over MoS 2 -confined Rh–Fe sites, which delivers an unprecedented CH 3 COOH selectivity of 90.3% and a productivity of 26.2 μmol g cat. –1 h –1 at 25 °C. Furthermore, the productivity of CH 3 COOH 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 CH 3 COOH. The confined Fe sites in MoS 2 enable the activation of O 2 to generate highly reactive Fe═O center for CH 4 dissociation to CH 3 species at room temperature, which then readily couple with adsorbed CO on adjacent Rh sites to form the key CH 3 CO intermediate for CH 3 COOH 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 CH 4 to CH 3 COOH under mild conditions.