Performance of Fe-N/C Oxygen Reduction Electrocatalysts toward NO2-, NO, and NH2OH Electroreduction: From Fundamental Insights into the Active Center to a New Method for Environmental Nitrite Destruction

Author(s)

Malko, Daniel ; Kucernak, Anthony ; Lopes, Thiago

• Document type: Journal article
• Source: Journal of the American Chemical Society; v. 138, n. 49, p. 16056-16068, DEC 14 2016.
• Web of Science Citations: 25

Abstract

Although major progress has recently been achieved through ex situ methods, there is still a lack of understanding of the 7 behavior of the active center in non-precious metal Fe-N/C catalysts under operating conditions. Utilizing nitrite, nitric oxide, and hydroxylamine as molecular probes, we show that the active site for the oxygen reduction reaction (ORR) is different under acidic and alkaline conditions. An in-depth investigation of the ORR in acid reveals a behavior which is similar to that of iron macrocyclic complexes and suggests a contribution of the metal center in the catalytic cycle. We also show that this catalyst is highly active toward nitrite and nitric oxide electroreduction under various pH values, with ammonia as a significant byproduct. This study offers fundamental insight into the chemical behavior of the active site and demonstrates a possible use of these materials for nitrite and nitric oxide sensing applications or environmental nitrite destruction. (AU)

• FAPESP's process: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Grantee: Julio Romano Meneghini
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• 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
• FAPESP's process: 16/07848-3 - Development of Electrocatalysts towards the Hydrogen Reactions
• Grantee: Thiago Lopes
• Support Opportunities: Scholarships in Brazil - Post-Doctoral