Scalable Gas Diffusion Electrode Fabrication for Electrochemical CO₂ Reduction Using Physical Vapor Deposition...

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Electrochemical CO2 reduction (ECR) is a key technology for sustainable chemical production and renewable energy storage.
• Optimizing catalyst integration within ECR devices is crucial for improving performance but remains understudied.

Purpose of the Study:

• To systematically investigate the impact of catalyst thickness and morphology on ECR performance using electron beam (EB) and magnetron-sputtered (MS) copper (Cu) coatings.
• To evaluate the scalability of optimized catalysts in a large-scale zero-gap electrolyzer.

Main Methods:

• Utilized a microfluidic gas diffusion electrolyzer to test EB-Cu and MS-Cu catalyst coatings with varying thicknesses and morphologies.
• Analyzed catalyst performance based on current density, selectivity, and energy efficiency.
• Conducted tests in a large-scale zero-gap electrolyzer to assess industrial applicability.

Main Results:

• EB-Cu catalysts exhibited superior performance compared to MS-Cu catalysts in terms of current density, selectivity, and energy efficiency.
• A catalyst thickness of 400 nm for EB-Cu showed optimal performance.
• The enhanced performance of EB-Cu was attributed to its faceted surface morphology and improved hydrophobicity at the Cu/gas diffusion layer interface.
• Similar product selectivity was achieved in large-scale tests, with an ethylene Faradaic efficiency of 39% at 200 mA/cm2.

Conclusions:

• Catalyst integration, specifically the morphology and thickness of copper coatings, significantly influences ECR device performance.
• Electron beam sputtering offers a promising method for fabricating high-performance ECR catalysts.
• The developed EB-Cu catalysts demonstrate scalability and potential for industrial electrochemical CO2 reduction applications.