Contact‐Electro‐Catalysis for Direct Oxidation of Methane under Ambient Conditions

Abstract

The conversion of methane under ambient conditions has attracted significant attention. Although advancements have been made using active oxygen species from photo‐ and electro‐ chemical processes, challenges such as complex catalyst design, costly oxidants, and unwanted byproducts remain. This study exploits the concept of contact‐electro‐catalysis, initiating chemical reactions through charge exchange at a solid‐liquid interface, to report a novel process for directly converting methane under ambient conditions. Utilizing the electrification of commercially available Fluorinated Ethylene Propylene (FEP) with water under ultrasound, we demonstrate how this interaction promote the activation of methane and oxygen molecules. Our results show that the yield of HCHO and CH3OH can reach 467.5 and 151.2 μmol·gcat‐1, respectively. We utilized electron paramagnetic resonance (EPR) to confirm the evolution of hydroxyl radicals (·OH) and superoxide radicals (·OOH). Isotope mass spectrometry (MS) was employed to analyze the elemental origin of CH3OH, which can be further oxidized to HCHO. Additionally, we conducted density functional theory (DFT) simulations to assess the reaction energies of FEP with H2O, O2, and CH4 under these conditions. The implications of this methodology, with its potential applicability to a wider array of gas‐phase catalytic reactions, underscore a significant advance in catalysis.

Contact-electro-catalysis under natural and industrial conditions: mechanisms, strategies, and challenges

“…For example, the recovery of waste lithium electrode materials 9 and precious metals 71 by CEC has recently been reported. Furthermore, CEC has been successfully used for nitrogen fixation, 70 methane oxidation, 72 and PFOA degradation, 63 potentially achieving organic synthesis, biomass conversion, tailing treatment, and air purification, among others. Further extensive contact electrochemistry research 112 will potentially expand CEC applications.…”

“…If the substrate is nitrogen, methane, or any other gas, the ROS produced by CEC reaction can convert these gases into valuable chemicals, such as ammonia and methanol. 70,72…”