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

• Published in: ACS applied materials & interfaces Vol. 14; no. 6; pp. 7731 - 7740
• Main Authors: Jeng, Emily, Qi, Zhen, Kashi, Ajay R, Hunegnaw, Sara, Huo, Ziyang, Miller, John S, Bayu Aji, Leonardus B, Ko, Byung Hee, Shin, Haeun, Ma, Sichao, Kuhl, Kendra P, Jiao, Feng, Biener, Juergen
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 16.02.2022; American Chemical Society (ACS)
• Subjects: carbon dioxide; catalyst morphology; catalysts; coating materials; copper catalyst; electrical properties; electrocatalysts; electrochemical CO2 reduction; electrochemistry; electrodes; energy efficiency; Energy, Environmental, and Catalysis Applications; ethylene; feedstocks; hydrophobicity; MATERIALS SCIENCE; physical vapor deposition; thickness; vapors; copper catalyst; electrochemical CO2 reduction; catalyst morphology; physical vapor deposition; energy efficiency
• DOI: 10.1021/acsami.1c17860
• ISSN: 1944-8244; 1944-8252

Electrochemical CO2 reduction (ECR) promises the replacement of fossil fuels as the source of feedstock chemicals and seasonal storage of renewable energy. While much progress has been made in catalyst development and electrochemical reactor design, few studies have addressed the effect of catalyst integration on device performance. Using a microfluidic gas diffusion electrolyzer, we systematically studied the effect of thickness and the morphology of electron beam (EB) and magnetron-sputtered (MS) Cu catalyst coatings on ECR performance. We observed that EB-Cu outperforms MS-Cu in current density, selectivity, and energy efficiency, with 400 nm thick catalyst coatings performing the best. The superior performance of EB-Cu catalysts is assigned to their faceted surface morphology and sharper Cu/gas diffusion layer interface, which increases their hydrophobicity. Tests in a large-scale zero-gap electrolyzer yielded similar product selectivity distributions with an ethylene Faradaic efficiency of 39% at 200 mA/cm2, demonstrating the scalability for industrial ECR applications.