3D Printed Nickel-Molybdenum-Based Electrocatalysts for Hydrogen Evolution at Low Overpotentials in a Flow-Through...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Hydrogen evolution reaction (HER) is crucial for clean energy production.
• Traditional electrode configurations face challenges with bubble formation and mass transport limitations.

Purpose of the Study:

• To synthesize and evaluate 3D printed NiMo electrocatalysts in a flow-through configuration for HER.
• To investigate the impact of hierarchical porosity and flow-through design on electrocatalytic performance.

Main Methods:

• Synthesis of 3D printed, hierarchically porous NiMo electrocatalysts using a resol-based aerogel precursor.
• Evaluation in a flow-through configuration within a simple electrochemical H-cell using 1.0 M KOH(aq).
• Development of an analytical model to assess voltage losses from kinetics, ohmic resistance, and bubble formation.

Main Results:

• The flow-through configuration effectively removed hydrogen bubbles, reducing overpotentials at high current densities.
• Achieved a high electrochemical surface area (ECSA) of 25163 cm² due to the porous structure.
• Demonstrated an average overpotential of 45 mV at 10 mA cm⁻² over 24 hours.

Conclusions:

• 3D printed NiMo electrocatalysts with hierarchical porosity and a flow-through configuration offer superior HER performance.
• The flow-through design enhances mass transport and minimizes bubble-induced losses.
• Findings provide valuable insights for adapting porous electrodes in flow cell applications.