Oxygen Reduction Reaction Electrocatalysis Using Dual-atom like Structures for Proton Exchange Membrane Fuel Cells

• Grant number: 24/11073-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2024
• End date: July 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Fabio Henrique Barros de Lima
• Grantee: Guilherme Henrique Siqueira Ghiraldelli
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 19/22183-6 - Electrocatalysis VI: fundamental and applied aspects of emerging and classical problems in electrochemical energy conversion, AP.TEM

Abstract

The development of stable and highly active electrocatalysts is essential to obtain clean and efficient energy conversion systems, such as fuel cells. Currently, Fe-N-C type electrocatalysts, which are iron atoms anchored on a nitrogen-doped carbon matrix, are promising as a substitute for platinum on the cathode, although, even with desirable activity, these materials face the challenge of stability, being degraded over a couple hours of use, preventing its use in larger scale. Based on the enzyme class of heme-copper oxidases, that have high stability and selectivity for the direct route of the oxygen reduction reaction (ORR), the synthesis of a material with an active site analogous to the bimetallic center of enzymes is promising to obtain electrocatalysts that are more stable and active. However, the synthesis of a material with a dual atom active site is considerably complex, therefore, the present project aims to synthesize a Metal@Fe-N-C (Metal= Cu, Mo, Ru, Co) type electrocatalyst, in which the metal is in the form of an encapsulated nanoparticle with a nitrogen-doped carbon shell containing iron single atoms (Fe-N-C), in a way that the resulting material has a high probability of having metal atoms close to iron atoms; i.e, reproducing the naturally occurring catalyst with bimetallic center. The activity and stability of the electrocatalyst on the ORR will be tested in electrochemical half-cells and unit fuel cells.