| Full text | |
| Author(s): |
do Rego, Ulisses Alves
[1, 2]
;
Sgarbi, Ricardo
[1]
;
Lopes, Thiago
[3]
;
dos Santos, Clenilton Costa
[4]
;
Tanaka, Auro A.
[4]
;
Ticianelli, Edson A.
[1]
Total Authors: 6
|
| Affiliation: | [1] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Carlos, SP - Brazil
[2] Univ Fed Maranhao, BR-65940000 Grajau, MA - Brazil
[3] Univ Sao Paulo, Res Ctr Gas Innovat, Escola Politecn, Ave Prof Mello Moraes 2231, BR-05508030 Sao Paulo, SP - Brazil
[4] Univ Fed Maranhao, BR-65080040 Sao Luis, MA - Brazil
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | ELECTROCATALYSIS; v. 12, n. 5, p. 548-563, SEP 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
In this work, several PGM-free materials supported on three types of carbon blacks (Vulcan XC-72, Monarch-1000, and Ketjenblack EC-600JD) and pyrolysed on N-2 and NH3 atmosphere are investigated as catalysts for the oxygen reduction reaction (ORR) in acid and alkaline electrolytes. The synthesized materials are characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The electrochemical characterization shows that for all N-2- and NH3-treated catalysts, the ORR activity is higher in alkaline than acidic conditions, though in both cases, the main reaction product is water, thus evidencing a predominant occurrence of a 4-electron oxygen reduction mechanism. Further, a reasonable relationship is established between Fe-N-x coordination (pyridinic-N) and pyrrolic-N contents and the ORR activity of catalysts in acid media (FeNx supported on Monarch-1000). In alkaline conditions, the iron coordination with pyridinic-N, coupled to a high carbon surface area (Ketjenblack), enhances the ORR activity regardless of the pyrolysis atmosphere. Finally, the ORR performance in alkaline medium of the FeNx/Ketjenblack catalyst pyrolysed under N-2 atmosphere is essentially the same as that achieved for the benchmark catalyst (Pt/C), while the durability of the best catalysts evidence to be quite promising in both acidic and alkaline media, as shown by a standard accelerated stability test. (AU) | |
| FAPESP's process: | 19/22183-6 - Electrocatalysis VI: fundamental and applied aspects of emerging and classical problems in electrochemical energy conversion |
| Grantee: | Edson Antonio Ticianelli |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 17/15304-6 - Electrocatalysis beyond platinum: development of sustainable electrocatalysts |
| Grantee: | Thiago Lopes |
| Support Opportunities: | Scholarships in Brazil - Young Researchers |
| FAPESP's process: | 14/22130-6 - Electrocatalysis beyond platinum: development of sustainable electrocatalysts |
| Grantee: | Thiago Lopes |
| Support Opportunities: | Research Grants - Young Investigators Grants |