Stainless steel supported NiCo2O4 active layer for oxygen evolution reaction

Autor(es)

Perroni, P. B. ; Ferraz, T. V. B. ; Rousseau, J. ; Canaff, C. ; Varela, H. ; Napporn, T. W.

• Tipo de documento: Artigo Científico
• Fonte: Electrochimica Acta; v. 453, p. 10-pg., 2023-04-07.

Resumo

The energy demand from a clean, renewable and cheap source has been increasingly urgent. In this work, a simple two steps preparation method was used to obtain NiCo2O4. NiCo2O4 layer was electrodeposited and calcined on two different stainless-steel alloys AISI 304 and AISI 316 L. The samples were characterized with XRD and XPS, which confirmed the material to be NiCo2O4. In both substrates the results suggest that the cat-alysts obtained, have good activity for OER, with an overpotential at 10 mA cm-2 of 360 and 340 mV for SS304 and SS316L respectively. However, the OER curve of the layer on SS316L achieves higher current density of 41.7 mA cm-2 while that on SS304 is 29.7 mA cm-2 at 1.7 V vs. RHE. The Tafel slope value shows better kinetics for the layer on SS304. From the EIS studies and the Nyquist plot the RCT for SS304 is 15.07 omega and for SS316L is 36.74 omega. This can be explained by the higher conductivity of SS304 which promotes the fast growth of nano-flowers with bigger nanopetals during the electrodeposition. The high material density in the surface causes crinkles, as can be seen in SEM analysis. This default in catalysts' morphology leads to a discontinuity in elec-trons transfer through the layer and then a decrease in kinetics. Another hypothesis is the presence of Mo in SS316L, which has a synergistic effect with the other metals. In this latter case the stainless-steel composition would have a direct influence on the reaction kinetics. (AU)

• Processo FAPESP: 19/22183-6 - Electrocatálise VI: aspectos fundamentais e aplicados em problemas emergentes e clássicos em conversão eletroquímica de energia
• Beneficiário: Edson Antonio Ticianelli
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 20/15230-5 - Centro de Pesquisa e Inovação de Gases de Efeito Estufa - RCG2I
• Beneficiário: Julio Romano Meneghini
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia