Kai Zheng, Mingyu Wu, Juncheng Zhu, Wei Zhang, Siying Liu, Xiaojing Zhang, Yang Wu, Li Li, Bangwang Li, Wenxiu Liu, Jun Hu, Chengyuan Liu, Junfa Zhu, Yang Pan, Meng Zhou, Yongfu Sun, Yi Xie
Photocatalytic conversion of methane (CH4 ) to ethane (C2 H6 ) has attracted extensive attention from academia and industry. Typically, the traditional oxidative coupling of CH4 (OCM) reaches a high C2 H6 productivity, yet the inevitable overoxidation limits the target product selectivity. Although the traditional nonoxidative coupling of CH4 (NOCM) can improve the product selectivity, it still encounters unsatisfied activity, arising from being thermodynamically unfavorable. To break the activity-selectivity trade-off, we propose a conceptually new mechanism of H2 O2 -triggered CH4 coupling, where the H2 O2 -derived ·OH radicals are rapidly consumed for activating CH4 into ·CH3 radicals exothermically, which bypasses the endothermic steps of the direct CH4 activation by photoholes and the interaction between ·CH3 and ·OH radicals, affirmed by in situ characterization techniques, femtosecond transient absorption spectroscopy, and density-functional theory calculation...
April 16, 2024: Journal of the American Chemical Society