Catalysis and Reaction Engineering Commons^™

Applications For The Quasi-Atomic Orbital And Constrained Density Functional Theory Methods On Catalytic Reactions, Alvaro David Loaiza Orduz

LSU Doctoral Dissertations

Selective activation of C–O, C–H, and C–C bonds underpins biomass upgrading, alkane functionalization, and CO₂ conversion. Despite their importance, the electronic factors governing catalytic performance remain incompletely understood, and many industrial processes still rely on empirical trends or material-specific observations. This dissertation addresses this gap by applying density functional theory (DFT), thermodynamic decomposition, and electronic-structure analysis to identify unifying principles of reactivity across transition-metal phosphides, vanadate oxides, copper-based electrocatalysts, and mixed IrO₂–RuO₂ layers. This work examines how charge transfer, orbital localization, and ligand-induced perturbations control reaction pathways in diverse catalytic systems. C–O bond scission in 2-methyltetrahydrofuran (MTHF) and methanol was …

Anion Exchange Membrane Transport And Accelerated Testing Methods For Co2 Electrolyzers With Cu-Based Electrocatalyst, John C. Hendershot

LSU Doctoral Dissertations

Electrocatalytic carbon dioxide (CO₂) reduction to C₂₊ products holds promise for low carbon intensity fuels, chemicals, and food; however, durability challenges, particularly bicarbonate (HCO₃^-)and carbonate (CO₃^2-) salt precipitation, hinder their commercialization. This report considers water (H₂O) and ion transport properties of conventional anion exchange membranes (AEMs) in zero-gap membrane electrode assembly (MEA) configurations using Cu electrocatalysts. Transport characterization includes H₂O diffusion, permeability, potassium (K⁺) diffusion, and transference numbers using three commercial AEMs, including piperidinium-based (Versogen), quaternary ammonium-based (Fumasep), and imidazolium-based (Dioxide Materials) membranes. Accelerated lifetime …

Low Temperature Methane Coupling With Co And Co2, A K M Kazi F.M. Aurnob

LSU Doctoral Dissertations

Methane is the smallest hydrocarbon and the most abundant component in natural gas. Despite its availability, its chemical utilization has remained limited due to the challenges associated with direct methane activation and conversion. Most of the methane oxidation and oxidative carbonylation reactions in literature have been carried out at high-pressure using batch reactors or at ambient pressure using flow reactors. While batch reactors have been shown to have higher product yields, they are limited in their capability to provide real-time kinetic insights and comprehensive mechanistic understanding of the reactions involved due to the long residence time. This limits rationalization of …

Induction Heating Driven Heterogeneous Catalysis: Magnetically Induced Nanoparticle Catalysts, Cameron Lee Roman

LSU Doctoral Dissertations

Heterogeneous catalysis has been and continues to be highly studied due to being one of the cornerstones of the chemical industry. With an increasing demand for chemicals and rising costs, there is a growing need to adapt to changing feed stocks and increase production efficiency. Polymers, oxygenates, and other chemical intermediates are predicted to experience continued growth, corresponding to an increased need for olefines. Due to the abundance of shale gas, researchers and producers are interested in meeting this demand via the dehydrogenation of light alkanes.

While dehydrogenation catalysts are a valuable tool in olefin production, selectivity and deactivation remain …

Computational Design Of Electro-Organocatalysts And Transition Metal Sulfides For The Electrochemical Reduction Of Co2, Foroogh Khezeli

LSU Doctoral Dissertations

Abstract

Electrochemical CO₂ reduction (ECO₂RR) has emerged as a promising approach for generating carbon-neutral liquid fuels by utilizing excess renewable electricity to convert CO₂. This thesis aims to employ atomistic simulations by using Density Functional Theory (DFT) to investigate the mechanistic details of how transition metal sulfides and electro-organocatalysts can enhance the activity and selectivity towards desired products, including those containing C-H bonds and molecules with C-C bonds. For this project, three different electrocatalysts were designed computationally.

Firstly, MoS₂ was chosen as a transition metal sulfide catalyst with the objective of understanding the kinetics …

Computational Study Of The Reactions Of Heteroatomic Compounds On Ceo2, Suman Bhasker Ranganath

LSU Doctoral Dissertations

The mechanisms of ambient-temperature reactions of heteroatomic compounds catalyzed by ceria (CeO₂), an archetypical reducible oxide, for enzyme mimetics, environmental protection, and chemical synthesis are investigated in this dissertation using theoretical methods. CeO₂ is modeled with thermodynamically stable low-index surfaces exposed by commonly studied ceria thin films and nano particles. To understand phosphatase-like dephosphorylation activity, stable adsorption states and surface reactions of model phosphates are examined. Binding of the central P-atom to surface lattice oxygen (O_latt) supplemented by phosphoryl O-Ce interaction is the only stable adsorption state for the un-dissociated molecule. Deprotonation of phosphate monoesters, …

Engineering The Surface Of Fe3o4 Nanoparticles For Catalytic And Magnetic Applications, Natalia Da Silva Moura

LSU Doctoral Dissertations

With the rapid depletion of the U.S. energy resources coupled with population growth, heat management technologies must be improved to sustain our quality of life. Precisely, in catalysis, it is estimated that only ~50% of the energy supplied to the reactor is used for product conversion due to dissipation losses. Among the emerging technologies with a promising reduction in heat losses is induction heating, offering targeted heat delivery with magnetic nanoparticles. Under alternating magnetic fields (AMF), these nanoparticles can absorb the energy from Radio-Frequency (RF) fields and dissipate it as heat on the nanoparticle surface. This in situ heat generation …

Direct Activation Of Light Alkanes To Value-Added Chemicals Using Supported Metal Oxide Catalysts, Md Ashraful Abedin

LSU Doctoral Dissertations

One of the most challenging aspects of modern-day catalysis is the conversion of methane. Direct conversion of methane via dehydroaromatization (MDHA) is a well-known process which can produce valuable hydrocarbons. Mo oxide supported on ZSM-5/MCM-22 has been studied extensively in recent years for MDHA. Mo carbides are responsible for activating methane by forming CHx species. These are dimerized into C2Hy and oligomerized on ZSM-5/MCM-22 Brønsted acid sites to form aromatics. Sulfated zirconia (SZ) supported Mo catalyst contains the acid sites necessary to produce benzene in MDHA. Here, sulfated hafnia (SH), a homologous oxide like SZ, has been proposed to provide …

Gold-Semiconductor Photocatalysts For Water Treatment Under Visible And Ultraviolet Light, Daniel Willis

LSU Doctoral Dissertations

Water scarcity threatens the lives of millions of people worldwide. It is imperative to improve the energy efficiency and affordability of water treatment methods to avoid a looming water-energy crisis. To meet this challenge, I have pursued research on the use of sunlight—our most reliable and abundant source of energy—to drive water treatment through photocatalysis. I explored the literature and found gold-semiconductor materials to hold promise for harvesting sunlight and catalyzing the breakdown of waterborne contaminants. Initially, I designed a novel optical cavity with gold (Au) nanoparticles on a zinc oxide / titania (TiO₂) / aluminum film stack …

Theoretical Investigation Of Fundamental Cathode Processes In Metal-02 Batteries, Saurin Hiren Rawal

LSU Doctoral Dissertations

In this thesis we theoretically explore the different fundamental phenomena associated with metal-air batteries (where the metal can be Li, Na or K) using first principles density functional theory. We start by investigating the adsorption of the starting reactants/primary intermediates i.e. metal superoxides and superoxide anion on Au(111) and Au(211). We elucidate the influence of electric fields and the importance of including explicit solvents on the adsorption energy of these intermediates. We show that these effects are considerable and should be included for future reaction modeling of these batteries. Following this we investigate the reaction of M⁺ and O …

Transition Metal-Doped Rare-Earth Oxysulfide Catalysts For High Temperature Dry Reforming Of Methane, Changyi Jiang

LSU Doctoral Dissertations

Carbon dioxide reforming of methane is a catalytic reaction utilizing two kinds of greenhouse gases and converting them into a useful industrial gas stream, “syngas”. However, sulfur poisoning and coke formation are two major challenges for this reaction. In this study, we have synthesized and examined several Ce-La and Ce-Zr oxides, with different transition metal additives. A rapid screening technique was developed to measure reforming and coking rates at low partial pressures. It is a good indicator of catalyst behavior at higher conversions and partial pressures. Following the rapid screening, select catalysts were examined at longer times on stream. Those …

First-Principle Study On The Interaction Of Ligands With Gold And Effects On Catalytic Activities, Xun Cheng

LSU Doctoral Dissertations

The extensive use of fossil fuels has increased the atmospheric concentration of CO₂, resulting in global climate change. One way to mitigate the CO₂ challenge is to convert it into useful chemicals electrocatalytically using renewable energies. Recent studies suggest that ligand-modified gold electrodes can enhance the Faradaic efficiency (FE) and selectivity of the electrochemical CO₂ reduction reaction (CO₂RR). This theoretical research, primarily based on density functional theory (DFT), has been carried out to understand the interactions of ligands with Au and possible effects on electrocatalytic activities. We systematically modeled and studied the adsorption of …

Natural Gas Conversion Into Value Added Chemicals Using Solid Acid Catalysts, Swarom Ravindra Kanitkar

LSU Doctoral Dissertations

Direct, non-oxidative conversion of natural gas to value-added chemicals has been identified as one of the grand challenges of the 21^st century. Circumventing indirect and costly reforming steps is highly sought after and solid acids can play an important role in that.

The direct conversion of methane to higher hydrocarbons and hydrogen can be catalyzed using “superacids” at < 450 °C. Reported superacid catalysts in solid, liquid, and gas phase included sulfated zirconia (SZ), HF-SbF₅, FSO₃H-SbF₅, and HBr-AlBr₃. Liquid and gas phase superacids presented difficulties in separation while the solid ones provided low yields. Here, we report a new class of Br-based solid superacids, AlBr_x/H-ZSM-5 (“ABZ-5”, …

First-Principles Study On The Catalytic Role Of Cerium Dioxide In The Conversion Of Organic Compounds, Chuanlin Zhao

LSU Doctoral Dissertations

Ceria is an earth-abundant material that has been widely used in heterogeneous catalysis, environmental catalysis, and energy applications thanks for its ability to readily convert between different oxidation states. The objective of this study is to theoretically elucidate the reaction mechanisms for the conversion of model organic compounds on ceria, in order to gain insights for the design of cost-effective and selective ceria-based catalysts. Acetaldehyde, acetic acid, and para-nitrophenyl phosphate monoester were selected as the model compounds to probe ceria surfaces. Density functional theory calculations can provide accurate predictions of adsorption and reaction energetics, which can be used to …

Engineering Metal-Ligand Interface For Selective Electrochemical Carbon Dioxide Reduction, Yuxin Fang

LSU Doctoral Dissertations

Unsustainable exploitation of fossil fuel and its massive greenhouse gas emission necessitates the development in alternative energy sources. Chemical fuels (CH₃OH or C₂H₅OH) outperform other choices, such as batteries for their high energy densities, which is key to portability. Electrochemical reduction of CO₂is capable of producing a wide range of valuable fuels (Syngas, formic acid, methane and methanol, etc.). Converting CO₂into carbon-based fuels further closes the carbon neutral cycle, which contributes to the effort in reducing global CO₂emission. Integration of organic ligands with transition metals shows great potential …

Electrocatalytic Properties Of Ni-Fe Basedalloys Toward Oxygen Evolution Reaction, Xiaodan Cui

LSU Doctoral Dissertations

In this dissertation, laser-based manufacturing was applied to develop NiFe-based alloys, with focus on their electrochemical characteristics toward oxygen evolution reaction during water electrocatalysis. The targeted electrocatalysts were designed by combining catalysis principles of absorption energy, electronic effect and geometry effect. Firstly, a one-step laser-based manufacturing method was applied to prepare a thin layer of NiFe-based electrodes with varied Ni to Fe ratios to replace high-cost noble metals as the electrocatalyst for oxygen evolution reaction (OER). Since each Ni has 0.6 d-vacancy and each Fe atom has 2.2 d-vacancies. The alloying of Ni-Fe allows electrons flowing from Ni to Fe, …

Experimental Evaluation Of Lignocellulosic Biomass Pyrolysis By Dielectric Heating And Thermocatalytic Upgrading Of Pyrolysis Vapors Via Iron-Doped Montmorillonite Clay Catalyst, Candice Raffaela Ellison

LSU Doctoral Dissertations

This work is an investigation of microwave-assisted biomass pyrolysis and thermocatalytic upgrading of pyrolysis vapors. In the first two chapters, the microwave susceptibility of mixtures of biomass with potential microwave absorbers are characterized by dielectric measurements at microwave frequencies. Dielectric constant and dielectric loss factor of biomass mixtures with char and biomass mixtures with bentonite are found to increase quadratically with increasing weight percent of char or bentonite.

Chapter 3 presents a finite element model, developed in COMSOL Multiphysics, comparing two waveguide applicator configurations for microwave processing using biomass as a model material. A standing wave configuration results in intense …