Direct conversion of methane to methanol by electrochemical methods

A convenient method for methane(CH_(4))direct conversion to methanol(CH_(3)OH)is of great significance to use methane-rich resources,especially clathrates and stranded shale gas resources located in remote regions.Theoretically,the activation of CH_(4) and the selectivity to the CH_(3)OH product are challenging due to the extreme stability of CH_(4) and relatively high reactivity of CH_(3)OH.The state-of-the-art‘methane reforming-methanol synthesis’process adopts a two-step strategy to avoid the further reaction of CH_(3)OH under the harsh conditions required for CH_(4) activation.In the electrochemical field,researchers are trying to develop conversion pathways under mild conditions.They have found suitable catalysts to activate the C–H bonds in methane with the help of external charge and have designed the electrode reactions to continuously generate certain active oxygen species.These active oxygen species attack the activated methane and convert it to CH_(3)OH,with the benefit of avoiding over-oxidation of CH_(3)OH,and thus obtain a high conversion efficiency of CH_(4) to CH_(3)OH.This mini-review focuses on the advantages and challenges of electrochemical conversion of CH4 to CH_(3)OH,especially the strategies for supplying electro-generated active oxygen species in-situ to react with the activated methane.