Executive Summary : | The design of an efficient, low-cost, and durable electrocatalyst for oxygen reduction reaction (ORR) remains a significant challenge in renewable energy and energy-intensive industries. The standard setup for ORR catalysis is a Pt or Pt alloy electrode, but non-Pt catalysts have been investigated as a low-cost alternative. Graphene-based nanocomposites, biomimetic approaches using 3d transition metal complexes of N4 macrocycles, and nonprecious metal oxides like TiO2, Fe3O4, perovskites, and spinels have been investigated as promising non-Pt catalysts, but their efficiency is far from that of Pt or Pt-alloy electrodes. Another essential contemporary desire is to develop durable and cost-effective sensors capable of detecting ultralow concentrations of analytes, such as explosives, ions, gases, and biomolecules. This project aims to develop a novel analytical platform based on the SHINERS approach to investigate the ORR reaction on different catalytic surfaces, focusing on comparative studies between noble metal-, non-precious metal oxide-, and biomimetic catalysts. The project will measure SER spectra as a function of potential for different electrode systems, assign vibrational bands using isotopically labeled oxygen, and derive binding energies under in situ conditions. Results obtained on Pt electrodes will be compared to non-precious metal oxide supports such as TiO2 and Fe3O4. The influence of the nanostructure itself will be investigated using different electrode morphologies. The project also aims to develop strategies that minimize the two electron reduction pathway while optimizing the 4 electron reduction pathway. |