Electrochemically Promoted Activation of Light Alkanes at Ambient Conditions

Abstract

The electrochemical activation of light alkanes into value-added products represents a promising pathway for sustainable chemical synthesis and the storage of renewable energy. In this study, we introduce an electrochemically promoted system that employs copper plates as electrode and oxygen as oxidant, capable of converting ethane into ethylene and acetic acid with production rates of 6.9 and 6.2 µmol·cm⁻²_Cu·h⁻¹, respectively, with a combined selectivity exceeding 92%, under ambient conditions. Additionally, this system can convert propane to propylene at a rate of 11.6 µmol·cm⁻²_Cu·h⁻¹, with selectivity reaching up to 86%. A 10 h run with ethane demonstrates consistent production of ethylene and acetic acid, with a sustained selectivity above 96%, and achieves an acetic acid concentration of 19 mM. In situ spectroscopic analysis reveals the active surface and a critical reaction intermediate. Combining with partial pressure dependence study and density functional theory (DFT) calculations, we propose a potential reaction mechanism involving the competitive adsorption of oxygen and alkane producing an alkyl group as a key reaction step in the reaction process.