Mild Methane Electrochemical Oxidation Boosted via Plasma Pre‐Activation

Abstract

AbstractObtaining partial methane oxidation reaction (MOR) with various oxygenates via a mild electrochemical method is practically difficult because of activation of stable C─H bond and consequent reaction pathway regulation. Here, a real‐time tandem MOR with cascaded plasma and electrocatalysis to activate and convert the methane (CH4) synergistically is reported for the first time. Boosted CH4 conversion is demonstrated toward value‐added products including, alcohols, carboxylates, and ketone via use of commercial Pd‐based electrocatalysts. Compared with hash industrial processes, a mild condition, that is, anode potential < 1.0 V versus RHE (reversible hydrogen electrode) is used that mitigates overoxidation of oxygenates and obviates competing reaction(s). One evidence that Pd(II) sites and surface adsorbed hydroxyls are important in facilitating activated‐CH4 species conversion, and establish a reaction mechanism for conversion(s) that involves coupling reactions between adsorbed hydroxyls, carbon monoxide and C1/C2 alkyls. One conclude that pre‐activation is important in boosting electrochemical partial MOR under mild conditions and will be of benefit in the development of sustainable CH4 conversion technology.