Catalysis

Oxide

Electrochemistry

Metallurgy

Materials science

Cyclic voltammetry

Spinel

Formic acid

Inorganic chemistry

Electrocatalyst

Physical chemistry

Nanotechnology

Organic chemistry

Glycerol

Cobalt oxide

Cobalt

Chemistry

Electrode

Nanostructure

Electrolyte

Electrolysis

Bulk electrolysis

ACS Catalysis

The electrochemical oxidation of abundantly available glycerol for the production of value-added chemicals, such as formic acid, could be a promising approach to utilize glycerol more effectively and to meet the future demand for formic acid as a fuel for direct or indirect formic acid fuel cells. Here we report a comparative study of a series of earth-abundant cobalt-based spinel oxide (MCo2O4, M = Mn, Fe, Co, Ni, Cu, and Zn) nanostructures as robust electrocatalysts for the glycerol oxidation to selectively produce formic acid. Their intrinsic catalytic activities in alkaline solution follow the sequence of CuCo2O4 > NiCo2O4 > CoCo2O4 > FeCo2O4 > ZnCo2O4 > MnCo2O4. Using the best-performing CuCo2O4 catalyst directly integrated onto carbon fiber paper electrodes for the bulk electrolysis reaction of glycerol oxidation (pH = 13) at the constant potential of 1.30 V vs reversible hydrogen electrode (RHE), a high selectivity of 80.6% for formic acid production and an overall Faradaic efficiency of 89.1% toward all value-added products were achieved with a high glycerol conversion of 79.7%. Various structural characterization techniques confirm the stability of the CuCo2O4 catalyst after electrochemical testing. These results open up opportunities for studying earth-abundant electrocatalysts for efficient and selective oxidation of glycerol to produce formic acid or other value-added chemicals.

Electrocatalytic Oxidation of Glycerol to Formic Acid by CuCo<sub>2</sub>O<sub>4</sub> Spinel Oxide Nanostructure Catalysts

Electrocatalytic Oxidation of Glycerol to Formic Acid by CuCo2O4 Spinel Oxide Nanostructure Catalysts

Electrocatalytic Oxidation of Glycerol to Formic Acid by CuCo₂O₄ Spinel Oxide Nanostructure Catalysts