Efficient electrochemical methane coupling enabled by stabilized oxygen species during oxygen evolution in a solid oxide electrolyzer integrated with CO₂ electrolysis

Abstract

The electrochemical oxidative coupling of methane (EOCM), integrated with CO₂ electrolysis enabled by high-temperature electrolysis technology, represents a promising pathway for methane utilization and carbon neutrality. However, progress in methane activation remains hindered by low C₂ product selectivity and limited reaction activity, primarily due to the lack of efficient and stable catalysts and rational design strategies. A critical focus of current research is the development of catalysts capable of stabilizing reactive oxygen species to facilitate C–H bond activation and subsequent C–C bond formation. Herein, an easily fabricated composite electrode consisting of perovskite La_0.6Sr_0.4MnO_3–δ and Ce-Mn-W materials with (Ce_0.90Gd_0.10)O_1.95 as the support was developed, demonstrating efficient activate methane activation. Combined theoretical and experimental investigations reveal that the designed composite electrode stabilizes active oxygen species during the oxygen evolution reaction (OER) while exhibiting superior methane adsorption capability. This design, leveraging oxygen species engineering and interfacial synergy, significantly enhances electrochemical methane coupling efficiency, establishing a strategic framework for advancing high-performance catalyst development.

Graphical abstract

Keywords

electrochemical oxidative coupling of methane (EOCM) / solid oxide electrolysis cell (SOEC) / methane to ethylene / composite electrode / CO₂ electrolysis

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Higher Education Press 2025