Renewable CH₄ produced from electrocatalytic CO₂ reduction is viewed as a sustainable and versatile energy carrier, compatible with existing infrastructure. However, conventional alkaline and neutral CO₂-to-CH₄ systems suffer CO₂ loss to carbonates, and recovering the lost CO₂ requires input energy exceeding the heating value of the produced CH₄. Here we pursue CH₄-selective electrocatalysis in acidic conditions via a coordination method, stabilizing free Cu ions by bonding Cu with multidentate donor sites. We find that hexadentate donor sites in ethylenediaminetetraacetic acid enable the chelation of Cu ions, regulating Cu cluster size and forming Cu-N/O single sites that achieve high CH₄ selectivity in acidic conditions. We report a CH₄ Faradaic efficiency of 71% (at 100 mA cm⁻²) with <3% loss in total input CO₂ that results in an overall energy intensity (254 GJ/tonne CH₄), half that of existing electroproduction routes.

由电催化 CO ₂还原产生的可再生 CH ₄被视为可持续的多功能能源载体，与现有基础设施兼容。然而，传统的碱性和中性CO ₂ -to-CH ₄系统遭受CO ₂损失为碳酸盐，并且回收损失的CO _{2需要超过产生的CH 4}的热值的输入能量。在这里我们追求 CH ₄- 通过配位法在酸性条件下进行选择性电催化，通过将 Cu 与多齿供体位点结合来稳定游离 Cu 离子。我们发现乙二胺四乙酸中的六齿供体位点能够螯合 Cu 离子，调节 Cu 簇大小并形成 Cu-N/O 单位点，从而在酸性条件下实现高 CH 4选择性_。我们报告了 CH ₄法拉第效率为 71%（在 100 mA cm ^-2时），总输入 CO ₂损失 <3% ，导致总体能量强度（254 GJ/吨 CH ₄），是现有电生产路线的一半.