Activity and stability investigation of the electrocatalysts constituted by abundant elements for the oxygen reduction reaction

Abstract

The development of fuel cells is linked to the overcoming some obstacles in order to allow the large-scale applications of these devices. Among them, high overpotentials and slow kinetics of oxygen reduction (ORR) on the cathodic electrode are highlighted, as well as the current dependence on the use of noble metals such as Pt and Pd, which do not present practical stability also increasing the cost of the device. In this sense, the investigation of electrocatalysts for the ORR, based on nanocomposites formed by carbon matrix doped with nitrogen and transition metals such as iron and cobalt (M-N-C), has been achieved a prominent role in the scientific community, due to the high electrocatalytic activities close to that achieved for platinum electrodes. Thus, in this project, M-N-C type materials are going to be synthesized and investigated using morphological characterization techniques (XRD, TEM, and BET) and electrochemical techniques such as cyclic voltammetry, polarization curves and potentiostatic and galvanostatic methods. The main goal is to understand the relationship between the electrocatalytic activity and the electrochemical stability for the ORR with the structure presented in these materials. More specifically, factors during the synthesis that influence the structure formed from these materials will be investigated, such as the precursor carbon source (carbon types with different surface areas) and the degree of doping and nitrogen precursor source (1,10-phenanthroline or other nitrogen-cointaining binding molecules). In addition, electrochemical stability tests will be carried out in unitaries fuel cells and the durability of the synthesized electrocatalysts will be determined for a real application in H2-O2 proton exchange membranes fuel cells (PEMFC). In this way, the project has scientific relevance for the country's technological development.