Theoretical Catalyst Design based on Asymmestrized Atomic and Electronic Structures

다국어 초록 (Multilingual Abstract)

Recent advancements in catalyst research emphasize energy-to-chemical conversion for storing renewable energy, particularly in reactions such as the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and carbon dioxide reduction reaction (CO2RR). Despite the clear advantages of commercial catalysts, such as their highly symmetrical and well-ordered structures that facilitate easier optimization, their performance is often limited by high costs, low activity, or poor stability. Novel strategies aim to improve conventional catalysts by introducing asymmetry into their atomic and electronic structures. These asymmetries include atomic- scale asymmetrizations like dopants, vacancies, and single-atom catalysts, as well as material-scale asymmetrizations like heterostructures, amorphous phases, and strain engineering. Despite these improvements, the increased structural complexity of these asymmetrically modified catalysts complicates the identification of their catalytic mechanisms. As a result, understanding these mechanisms via density functional theory (DFT) studies is essential. In this work, I will discuss several theoretical approaches using DFT simulations to identify high-performance catalysts with asymmetrically altered atomic and electronic structures, ranging from the atomic to material scales across various reactions. For example, in CO2RR, I will discuss the impact of single atom metal (Fe, Cu) dispersed on TiO2 and how it influences CO2RR performance. Additionally, I will examine the photocatalytic properties and CO2 adsorption behavior of amorphous TiO2/CdSe compared to crystalline TiO2/CdSe. For the discussion on the oxygen evolution reaction (OER), I will elaborate on how the incorporation of atomic-level La dopants alters the electronic structure of NiFe- LDH and enhances its OER performance. Lastly, I will address the effect of tensile and compressive strain engineering to Au on HER and ORR.

목차 (Table of Contents)

• Chapter 1. Introduction 1
• 1.1 Carbon-Mediated Conversion: CO2 Reduction 1
• 1.2 Water-Mediated Conversion: H2/O2 Evolution and O2 Reduction 3
• Chapter 2. Atomic Scale Asymmetrization I: Single-Atom Catalyst 5
• 2.1 Computational Details 5
• 2.2 Results and Discussions 6
• Chapter 3. Material Scale Asymmetrization I: Amorphous Structure 12
• 3.1 Computational Details 12
• 3.2 Results and Discussions 15
• Chapter 4. Atomic Scale Asymmetrization II: Metal-Doped Catalyst 24
• 4.1 Computational Details 24
• 4.2 Results and Discussions 25
• Chapter 5. Material Scale Asymmetrization II: Strain Engineering 31
• 5.1 Computational Details 31
• 5.2 Results and Discussions 33
• Chapter 6. Conclusions 41
• References 42