Ag<sup>II</sup>‐Mediated Electrocatalytic Ambient CH<sub>4</sub> Functionalization Inspired by HSAB Theory
Danlei Xiang, Jesus A. Iñiguez, Jiao Deng, Xun Guan, Antonio Martínez, Chong Liu
Abstract
Abstract Although most class (b) transition metals have been studied in regard to CH 4 activation, divalent silver (Ag II ), possibly owing to its reactive nature, is the only class (b) high‐valent transition metal center that is not yet reported to exhibit reactivities towards CH 4 activation. We now report that electrochemically generated Ag II metalloradical readily functionalizes CH 4 into methyl bisulfate (CH 3 OSO 3 H) at ambient conditions in 98 % H 2 SO 4 . Mechanistic investigation experimentally unveils a low activation energy of 13.1 kcal mol −1 , a high pseudo‐first‐order rate constant of CH 4 activation up to 2.8×10 3 h −1 at room temperature and a CH 4 pressure of 85 psi, and two competing reaction pathways preferable towards CH 4 activation over solvent oxidation. Reaction kinetic data suggest a Faradaic efficiency exceeding 99 % beyond 180 psi CH 4 at room temperature for potential chemical production from widely distributed natural gas resources with minimal infrastructure reliance.