High-Current-Density Glycerol Electrooxidation on S-Cu-Ni/NF Catalyst: Unveiling the Synergy between S-Promoted GOR...

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrocatalytic glycerol oxidation reaction (GOR) coupled with hydrogen evolution reaction (HER) is a promising route for hydrogen production.
• Challenges remain in achieving stable glycerol degradation to formate at high current densities due to competing oxygen evolution reaction (OER) at high potentials.

Purpose of the Study:

• To develop a stable and efficient catalyst for glycerol oxidation to formate coupled with hydrogen evolution.
• To suppress the oxygen evolution reaction (OER) and enhance the glycerol oxidation reaction (GOR) performance at high potentials.

Main Methods:

• Synthesis of S-Cu-Ni/NF catalysts using Cu-Ni/NF precursors.
• Electrocatalytic performance testing for GOR and HER.
• Characterization using SEM-EDS, XPS, and in situ Raman spectroscopy.

Main Results:

• The S-Cu-Ni/NF catalyst demonstrated over 75% formate Faraday efficiency across a wide potential range (1.3-1.6 V vs RHE) by suppressing OER.
• Achieved a high current density of 100 mA cm⁻² at 1.395 V vs RHE with significantly enhanced GOR performance.
• Exhibited excellent stability with only a 40 mV potential increase after 24 hours of operation at 100 mA cm⁻².
• Characterization confirmed sulfur precipitation promotes NiOOH active site formation and growth during GOR.

Conclusions:

• The S-Cu-Ni/NF catalyst effectively inhibits OER, improving formate selectivity at high potentials.
• The catalyst significantly enhances GOR performance and demonstrates potential for stable glycerol degradation at high current densities.
• Provides a viable strategy for industrial application of glycerol oxidation coupled with hydrogenolysis.