Electrooxidation of Ethanol to Acetate on Mix-Phase Nickel-Manganese Composites in Alkaline Environment

Abstract

Electrochemically oxidizing ethanol to acetate at the anode represents a promising alternative to the oxygen evolution reaction, enabling energy-efficient hydrogen evolution at the cathode. Herein, bimetallic NiMnOx composites were synthesized via hydrothermal method using nickel nitrate and potassium permanganate as precursors. Detailed electrochemical tests showed 5NiMnOx exhibited optimal ethanol oxidation reaction (EOR) activity (net current density 8.8 mA cm 2) and a maximum acetate Faradaic efficiency (FE) of 81.4% at 1.6 V vs. RHE, with stable performance over 12 h. DFT calculations demonstrated Ni doping modulates electronic structures, shifting Mn 3d bands toward Fermi level and reducing the EOR rate-determining step barrier from 4.95 eV (pristine MnOOH) to 3.10 eV. Together, these insights highlight the potential of nickel–manganese oxides as cost-effective and stable catalysts for integrated hydrogen production and biomass-derived chemical manufacturing.