Oxygen reduction reaction mechanism and kinetics on M-N(x)C(y)and M@N-C active sites present in model M-N-C catalysts under alkaline and acidic conditions

Autor(es)

Sgarbi, Ricardo ^{[1, 2]} ; Kumar, Kavita ^[2] ; Jaouen, Frederic ^[3] ; Zitolo, Andrea ^[4] ; Ticianelli, Edson A. ^[1] ; Maillard, Frederic ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560960 Sao Carlos, SP - Brazil

^[2] Univ Grenoble Alpes, Univ Savoie Mt Blanc, CNRS, Grenoble INP, LEPMI, F-38000 Grenoble - France

^[3] Univ Montpellier, CNRS, ENSCM, UMR Inst Charles Gerhardt Montpellier 5253, 2 Pl Eugene Bataillon, F-34095 Montpellier - France

^[4] Synchrotron Soleil, BP 48 St Aubin, F-91192 Gif Sur Yvette - France

• Tipo de documento: Artigo Científico
• Fonte: Journal of Solid State Electrochemistry; v. 25, n. 1, SI, p. 45-56, JAN 2021.
• Citações Web of Science: 25

Resumo

M-N-C electrocatalysts (where M is Fe or Co) have been investigated for mitigating the dependence on noble metals when catalyzing the oxygen reduction reaction (ORR) for fuel cell technologies in acidic or alkaline conditions. Rotating disk and rotating ring-disk electrode measurements for Fe-N-C and Co-N-C catalysts demonstrate promising performances and stability for the ORR, while the activity of main suspected active sites (M-N(x)C(y)and M@N-C) has been discussed on the basis of the known physical-chemical properties of the catalysts in acid and alkaline media. Thereupon, it is observed that atomically dispersed Fe-N(x)C(y)sites reach the highest ORR activity in acid media when amplified by an adequate energy binding between the metallic center and the oxygenated reaction intermediates. In contrast, Fe@N-C core-shell sites reach a maximum ORR mass activity in alkaline media through a synergistic effect involving catalyst particles with metallic iron in the core and nitrogen-doped carbon in the shell. (AU)

• Processo FAPESP: 13/16930-7 - Eletrocatálise V: processos eletrocatalíticos de interconversão entre as energias química e elétrica
• Beneficiário: Edson Antonio Ticianelli
• Modalidade de apoio: Auxílio à Pesquisa - Temático