Choe, Seunghoe Lee, Byung-Seok Jang, Jong Hyun 2024-01-20T02:02:46Z 2024-01-20T02:02:46Z 2021-09-01 2017-03 2093-8551 https://pubs.kist.re.kr/handle/201004/123017 This study aims to examine the influences of substrates/diffusion layers (DL) and oxygen reduction reaction catalysts (M-ORR) on the performance of M-ORR/IrO2/DL-type bifunctional oxygen electrodes for use in polymer electrolyte membrane (PEM)-type unitized regenerative fuel cells (URFC). The M-ORR/IrO2/DL electrodes were prepared via two sequential steps: anodic electrodeposition of IrO2 on various DLs and fabrication of M-ORR layers (Pt, Pd, and Pt-Ru) by spraying on IrO2/DL. Experiments using different DLs, with Pt as the M-ORR, revealed that the roughness factor of the DL mainly determined the electrode performance for both water electrolyzer (WE) and fuel cell (FC) operations, while the contributions of porosity and substrate material were insignificant. When Pt-Ru was utilized as the M-ORR instead of Pt, WE performance was enhanced and the electrode performance was assessed by analyzing round-trip efficiencies (epsilon(RT)) at current densities of 0.2 and 0.4 A/cm(2). As a result, using Pt-Ru instead of Pt alone provided better epsilon(RT) at both current densities, while Pd resulted in very low epsilon(RT). Improved efficiency was related to the additional catalytic action by Ru toward ORR during WE operation. English KOREAN ELECTROCHEMISTRY SOC ELECTROCATALYST OPTIMIZATION EFFICIENCY CORROSION DESIGN Effects of Diffusion Layer (DL) and ORR Catalyst (M-ORR) on the Performance of M-ORR/IrO2/DL Electrodes for PEM-Type Unitized Regenerative Fuel Cells Article 10.5229/JECST.2017.8.1.7 1 JOURNAL OF ELECTROCHEMICAL SCIENCE AND TECHNOLOGY, v.8, no.1, pp.7 - 14 JOURNAL OF ELECTROCHEMICAL SCIENCE AND TECHNOLOGY 8 1 7 14 scie scopus 000404287100002 2-s2.0-85020455311 Electrochemistry Electrochemistry Article ELECTROCATALYST OPTIMIZATION EFFICIENCY CORROSION DESIGN Polymer electrolyte membrane unitized regenerative fuel cell Bifunctional oxygen electrode Membrane electrode assembly Diffusion layer Electrocatalyst