Design principles for efficient oxygen reduction electrocatalysts: unveiling structure-activity relationships in non-noble metal systems

Abstract

The first chapter of this thesis thoroughly surveys major topics in electrocatalysis, placing particular emphasis on the ORR mechanisms on novel materials including perovskite oxides, CNTs, and 2D TMDs. The present work analyzes the structural and electronic properties of perovskite oxides, CNTs, and 2D TMDs and assesses their activity as ORR electrocatalysts. The second chapter of this thesis describes the methodology used in this study. It presents an overview of computational science and theoretical methods and discusses how computational materials science interface with chemistry. The third chapter of this thesis encompasses the design of a 2D monolayer LaNiO3. First, we investigated its electronic properties, focusing specifically on the energy band structure and total density of states (DOS). We then evaluated the electrocatalytic performance of 2D monolayer LaNiO3 for the oxygen reduction reaction (ORR) by mapping its complete reaction pathways and mechanisms. To quantify these processes, DFT simulations were employed to calculate the relative Gibbs free energy (ΔG) of each reaction intermediates. The fourth chapter of this thesis includes the computational designing of CoPt nanoparticle encapsulated in carbon nanotube (CoPt@CNT). The structural and electronic properties of the CoPt@CNT was explored employing DFT-D3 method to study its catalytic activity towards ORR. The ORR mechanism both associative and dissociative pathways have been explored on the surface of the CoPt@CNT by computing the relative adsorption energy (ΔE) and Gibbs free energy (ΔG) of key reaction intermediates. In the fifth chapter of this thesis, we have computationally designed the FeCe nanoparticle encapsulated carbon nanotube (FeCe@CNT). The electronic structural properties, electronic band gap, total density of states (DOS) were investigated using DFT-D3 method. The whole ORR mechanism was explored on the FeCe@CNT surface by computing relative adsorption energy. In the sixth chapter of this thesis, a Mo defective 2D monolayer MoTe2 was studied. We investigated the electronic structural properties and electronic band