SILVA, JULIO C.M.ASSUMPÇAO, MONICA H.M.T.HAMMER, PETERO. NETO, ALMIRSPINACE, ESTEVAM V.BARANOVA, ELENA A.2018-02-222018-02-222017SILVA, JULIO C.M.; ASSUMPÇAO, MONICA H.M.T.; HAMMER, PETER; O. NETO, ALMIR; SPINACE, ESTEVAM V.; BARANOVA, ELENA A. Iridium-rhodium nanoparticles for ammonia oxidation: electrochemical and fuel cell studies. <b>ChemElectroChem</b>, v. 04, n. 05, p. 1101-1107, 2017. DOI: <a href="https://dx.doi.org/10.1002/celc.201600701">10.1002/celc.201600701</a>. Disponível em: http://repositorio.ipen.br/handle/123456789/28533.2196-0216http://repositorio.ipen.br/handle/123456789/28533This study reports the use of carbon-supported IrRh/C electrocatalysts with different iridium-to-rhodium atomic ratios (0 : 100, 50: 50, 70: 30, 90: 10, and 100: 0) for ammonia electro-oxidation (AmER) in alkaline media. The materials prepared by using the sodium borohydride method showed a mean diameter of 4.5, 4.8, 4.2, and 4.5 nm for Ir/C, Ir90Rh10/C, Ir70Rh30/C, and Ir50Rh50/C, respectively. According to electrochemical and fuel cell experiments, the Ir50Rh50/C catalyst was the most promising towards AmER. This catalyst, which consisted predominantly of the metallic Ir/Rh phases, showed a 500% higher current density and 55% higher maximum power than that obtained for Ir/C. After 8 h galvanostatic electrolysis, 93% of initial ammonia was degraded when using Ir50Rh50/C, whereas it was only 70% with Ir/C. The high activity of the Ir50Rh50/C is attributed to a synergic effect of two metals at this iridium-to-rhodium ratio, which enhances the kinetics of AmER contributing towards ammonia dehydrogenation at lower potentials.1101-1107closedAccessnanoparticlesiridiumrhodiumammoniaoxidationfuel cellselectrochemical cellsArtigo de periódico050410.1002/celc.201600701https://orcid.org/0000-0002-7011-8261https://orcid.org/0000-0002-9287-607176.79