Highly Efficient Methane Electrosynthesis Enabled by Precise, Multifaceted Interface Regulation

The electrocatalytic reduction of carbon dioxide (CO 2 ) offers a pathway to transform greenhouse gas emissions into fuels and chemicals using renewable electricity. Among possible products, methane (CH 4 ) is particularly attractive due to its high energy density and seamless integration with existing natural gas infrastructure, yet its electrosynthesis is hindered by demanding multi-electron kinetics and mass-transport constraints. Here, we report a four-channel copper tubular penetration electrode (TPE) with a honeycomb-like architecture that fundamentally reshapes the reaction environment for CO 2 electroreduction. By precisely controlling electrode cross-sectional thickness, this multi-channel design regulates gas, electron, and electrolyte transport, stabilizing the three-phase interface required for efficient CH 4 formation. The optimized TPE achieves a CH 4 Faradaic efficiency of 87.5%, a half-cell energy efficiency of 43.46%, and stable operation for 100 hours. Combined experimental and theoretical analyses reveal that rational design of electrode architecture enables precise control over the CO 2 adsorption configurations and reaction intermediates, thereby fine-tuning the reaction pathway toward CH 4 . These findings establish multi-channel TPEs as a powerful platform for efficient CO 2 electromethanation.