NiOX-Pt/C nanocomposites: Highly active electrocatalysts for the electrochemical oxidation of hydrazine

Author(s)

de Oliveira, Drielly C. ; Silva, Wanderson O. ; Chatenet, Marian ; Lima, Fabio H. B.

• Document type: Journal article
• Source: APPLIED CATALYSIS B-ENVIRONMENTAL; v. 201, p. 22-28, FEB 2017.
• Web of Science Citations: 15

Abstract

NiOx-modified Pt/C nanocomposites are synthesized and investigated for hydrazine electrooxidation in an alkaline electrolyte. The reaction onset potential is significantly reduced in comparison to that of pure Pt/C, owing to the occurrence of a bifunctional mechanism, in which OH species on Ni sites facilitate the oxidation of adsorbed H atoms on the Pt surface. On-line Differential Electrochemical Mass Spectrometry (DEMS) shows that NiOx-Pt/C catalyzes the heterogeneous chemical hydrolysis at open circuit potential, producing H-2 and N-2.Just above the OCP, the H-2 signal in DEMS decreases concomitantly with the increase in faradaic current, due to quantitative H-2 (and Had) electrooxidation on Pt, or due to the deceleration of the overall reaction of hydrolysis. At slightly higher potentials, the N-2 signal further rises, which indicates the onset of complete electrooxidation of hydrazine. In the platinum-oxide region, the H-2 signal increases again and this process is also accompanied by a small ionic signal of NH3, evidencing the occurrence of an incomplete hydrazine electrooxidation route, at least in a minor extent. (C) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 11/50727-9 - Development of systems for hydrogen production and for the generation and utilization of electrochemical energy
• Grantee: Ernesto Rafael Gonzalez
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/16930-7 - Electrocatalysis V: electrocatalytic processes of chemical and electrical energy interconversion
• Grantee: Edson Antonio Ticianelli
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/12232-3 - Study of the hydrazine and borohydride ions electro-oxidation reaction on non-noble metal electrocatalysts for alkaline fuel cells
• Grantee: Drielly Cristina de Oliveira
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 13/00197-9 - Study of the hydrazine and borohidride ions electro-oxidation reaction on non-noble metal electrocatalysts for alkaline fuel cells.
• Grantee: Drielly Cristina de Oliveira
• Support Opportunities: Scholarships in Brazil - Doctorate