Revealing the Role of Mn–O Bonds in Electrocatalytic Methanol Oxidation to Value-Added Formate in LaMnO₃

Understanding the structure–activity relationships in perovskite catalysts is essential for advancing renewable electrochemical energy technologies. This study reports the exceptional performance of LaMnO3 deposited on nickel foam (NF) electrodes in selective methanol electrooxidation. Experimental analyses reveal that the preferred crystalline facets of LaMnO3 grown on nickel foams predominantly generate {110} facets, and this facet engineering effectively promotes the adsorption of methanol molecules. Moreover, the electronic structure of the Mn–O bonds on the LaMnO3 surface has been optimized, resulting in good activity and approximately 100% Faradaic efficiency (FE) at current densities ranging from 100 to 500 mA cm–2. Notably, the total FE for formate demonstrates durability for up to 10 h at 100 mA cm–2, with selectivity exceeding 86%. This results in a substantial reduction (∼15.88%) in energy consumption for producing pure hydrogen. In situ studies indicate that the unique structure of LaMnO3/NF facilitates the formation of high-valent active Mn–O species and stabilizes the crystalline framework through an interfacial Mn–O network. This configuration provides abundant active sites and oxygen sources for converting methanol to formate, establishing a stable and efficient catalytic environment.