Manganese Doped-Nitrogenated Carbon as an Efficient Catalyst for Acidic Electrocatalytic Reduction of CO 2 .

Renewable electricity-driven CO 2 electroreduction to value-added chemicals is a feasible approach to alleviate both environmental and energy issues. However, CO 2 reduction reaction (CO 2 RR) systems in alkaline electrolytes are constrained by intrinsic limitations such as salt accumulation that impede further industrialization. Herein, an atomically dispersed Mn doped-nitrogen carbon (AD MnNC) catalyst is developed to electrochemically reduce CO 2 to CO in both neutral and acidic media. Benefiting from well-dispersed MnN x sites, the maximum CO Faradaic efficiency (FE CO ) reaches ≈100% at -0.73 V versus reversible hydrogen electrode (RHE) with CO current density (J CO ) of 20.4 mA cm -2 in neutral 0.5 m KHCO 3 . Due to diminished * H adsorption, AD MnNC achieves a FE CO of 85.3% at pH 2.0, effectively suppressing the hydrogen evolution reaction (HER) in an acidic electrolyte. The mechanistic study reveals that AD MnNC accelerates the production of * COOH intermediates through a proton-coupled electron transfer (PCET) pathway and thus promotes CO formation.