Oxygen reduction electrocatalysis on transition metal-nitrogen modified tungsten carbide nanomaterials

Author(s)

do Rego, Ulisses Alves ^{[1, 2]} ; Lopes, Thiago ^[1] ; Bott-Neto, Jose Luiz ^[1] ; Tanaka, Auro Atsushi ^[2] ; Ticianelli, Edson Antonio ^[1]

Affiliation

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

^[2] Univ Fed Maranhao, BR-65080040 Sao Luis, MA - Brazil

• Document type: Journal article
• Source: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 810, p. 222-231, FEB 1 2018.
• Web of Science Citations: 5

Abstract

Considering the technological importance of the oxygen reduction reaction (ORR) and the cost constraints of highly catalytically active precious metals, recent research efforts have been focused on designing and synthesizing earth abundant non-precious metal catalysts for this reaction. Among recent advances in this area, transition metal-nitrogen modified tungsten carbides can be pointed as prominent candidates as ORR electrocatalysts. Nevertheless, mechanistically understandings of which active sites are responsible for the ORR electrocatalysis on these materials are required for the rational design of suitable materials. In the present work, various tungsten carbides and iron-nitrogen modified tungsten carbides catalysts are synthesized and in-depth characterized through various physical and electrochemical techniques towards gaining insights on the ORR process on these materials in both acidic and alkaline media. High performance materials are developed, with the most active presenting only a ca. 0.060 V increase in the ORR overpotential, compared to a standard platinum catalyst in an alkaline medium. The in-depth analyses allowed for suggestions on reaction pathways for the oxygen reduction on the hybrid Fe/N/WC/C nanomaterials in terms of active sites. These finds might direct further developments in the research on transition metal-nitrogen modified tungsten carbide materials. (AU)

• FAPESP's process: 14/22130-6 - Electrocatalysis beyond platinum: development of sustainable electrocatalysts
• Grantee: Thiago Lopes
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Grantee: Julio Romano Meneghini
• Support Opportunities: Research Grants - Applied Research Centers Program
• 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: 17/15304-6 - Electrocatalysis beyond platinum: development of sustainable electrocatalysts
• Grantee: Thiago Lopes
• Support Opportunities: Scholarships in Brazil - Young Researchers
• FAPESP's process: 14/09087-4 - Studies on the use of bioethanol in proton exchange membrane and solid oxide fuel cells
• Grantee: Marcelo Linardi
• Support Opportunities: Research Projects - Thematic Grants