Year: 2026
Type: article
Abstract: The development of carbon alloy ORR catalysts requires practical methods for their characterization and comparison. In this study, two carbon alloy ORR catalysts (CA and CA-Fe), together with a Pt/C reference, were characterized using rotating ring–disk electrode (RRDE) measurements over a range of catalyst loadings. The conventional RRDE metrics, the half-wave potential ( E 1/2 ) and hydrogen peroxide yield ( f H2O2 ), exhibit different loading dependences. As a result, direct comparison of catalyst characteristics becomes difficult. To address this limitation, we developed a descriptor-based characterization framework. It employs two phenomenological descriptors, k f2 and k s2 . They were derived from RRDE linear-sweep voltammetry within a simplified reaction–diffusion framework. The descriptor k f2 represents the overall tendency of H 2 O 2 formation. The second descriptor, k s2 , represents the overall disappearance of H 2 O 2 within the catalyst layer as reflected in the RRDE response. Both descriptors showed only small variations with catalyst loading and electrode rotation rate under the present experimental conditions. As a proof of concept, CA, CA-Fe, and Pt/C were mapped onto this descriptor space. Each catalyst occupied a distinct position. These results demonstrate that the framework provides a common basis for characterizing and comparing the catalyst systems examined in this study.
Source: Carbon Trends
Institutions: Gunma University, Nisshinbo Holdings (Japan)
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,000
OpenAlex ID: W7204909733