Chemical Engineering Commons^™

Electroless Deposition And Galvanic Displacement For The Control Of Supported Nanoparticle Size And Composition, Haiying Zhou

Theses and Dissertations

Catalyst performances can be greatly affected by properties such as particle size, composition, geometry, and cleanliness of the active surface. To achieve optimal catalytic performance, appropriate synthesis methods are required to synthesize the desired structures. Supported metal particle catalysts are usually prepared by impregnation and precipitation methods in industry. Although these two methods are simple, they exhibit poor control over surface morphology, leading to a wide particle size distribution and uncontrolled distribution of different metal components. In this dissertation, three topics on controlling surface morphology are discussed.

For structure sensitive reactions, reactivity and selectivity can be strongly affected by particle …

Rational Catalyst Synthesis For Sustainable Energy Applications, Alaba Upe Ojo

Theses and Dissertations

Energy accounts for two-thirds of the global climate challenges. Effective utilization of green hydrogen or finding cleaner ways to improve energy generation is necessary to combat climate crisis and allow for a more sustainable future. This work evaluates three heterogeneous catalytic processes which contribute to a sustainable future. In chapter 2, we studied the hydrogenation of toluene to methylcyclohexane; a reaction that can potentially serve as a medium for hydrogen storage and help to overcome the safety challenges of transporting gaseous hydrogen. We found that palladium catalysts on certain carbons exhibited significantly enhanced toluene hydrogenation rates compared to activated carbons …

Addressing Strain And Porosity Changes Of Battery Electrodes Due To Reversible Expansion Through Dem Simulations, Hunter Teel, Taylor R. Garrick, Srikant Srinivasan, Fengkun Wang, Yangbing Zeng, Sirivatch Shimpalee

Faculty Publications

In this work, discrete element method (DEM) simulations were used to probe changes in electrode porosity, electrode strain, and the resultant pressure changes for composite electrodes comprised of active material and binder particles. Through the results acquired by these simulations, three cases that are representative of two limiting cases for electrode operation, and one case for realistic electrode face pressure during operation were captured and the implications on design and performance are discussed. Predicting changes in the porosity is a unique insight that is difficult if not impossible to capture experimentally but is important for predicting changes in electrochemical performance …

Quantifying The Impact Of Microstructure Variation On Charging Capability In Lithium-Ion Batteries, Hunter Teel, Taylor R. Garrick, Mitchell A. Sepe, Joseph S. Lopata, Srikant Srinivasan, Fengkun Wang, Yangbing Zeng, Sirivatch Shimpalee

Faculty Publications

Through the use of electrochemical simulations, variation in the local onset of lithium plating can be predicted and used to set charging guidelines to reduce the risk of lithium plating. The pseudo-two-dimensional (P2D) model is typically used for capturing this behavior; however, it only provides a global lithium plating onset estimate and does not consider the local variation. With material properties translated to an average continuum value, the P2D model can simulate rapid charge and capture global onset of lithium plating. However, this model lacks the ability to resolve localized behaviors across individual components due to local non-uniformities. Our three-dimensional …

Guiding 3d Chiral Self-Assembly At Nano/Micro Length Scales Via 3d Printing, Mohsen Esmaeili

Theses and Dissertations

This thesis delves into the intricate realm of 3D printing bio-inspired materials with tailored nano/microscale architectures. The first chapter investigates the flow-induced alignment of cellulose nanocrystals (CNC) during 3D printing, employing a microfluidic strategy integrated with polarized optical microscopy (POM). Birefringence measurements under varying conditions reveal the influence of initial CNC suspension structures on flow-induced patterns, particularly in the chiral nematic phase. Hydrodynamic simulations complement experimental findings, elucidating the impact on CNC particle alignment, providing insights for designing 3D printed architectures with internal chirality for advanced applications.

The second chapter explores the 3D printing of complex geometries inspired by Bouligand …

Mathematical Modeling And Reconstruction Of Porous Media To Understand Transport Phenomena For Electrochemical System Applications, Mitchell Sepe

Theses and Dissertations

Alternative power generation has grown significantly in the space of energy production over the last ten years. Development of new technologies to produce energy is vital to the growing need for electricity. Batteries, solar panels, wind turbines, and countless other renewable energy options have been deemed necessary to create an overall greener future. Fuels cells when combined with electrolyzer show a promising system for stationary power generation. Both technologies are comprised of multiple parts in contact that must work together simultaneously to create an ideal environment for catalytic reactions to take place. A crucial component to a properly functioning cell …

A Click Chemistry Amplified Nanopore Assay For High Performance Testing Of Protein Biomarkers In Diseases, Xiaoqin Wang

Theses and Dissertations

Nanopore detection technology enables nanometer-scale single-molecule detection, yielding valuable insights into analyte molecules' properties such as size, shape, charge, and concentration. Due to its label-free nature, high sensitivity, and real-time capabilities, it finds widespread application in genomics, proteomics, drug discovery, and environmental monitoring. Click chemistry, encompassing the attachment of a probe or substrate to a biomolecule, termed bioconjugation, features the copper-catalyzed azide-alkyne cycloaddition as a quintessential reaction, forming a 5-membered heteroatom ring. This study harnesses this reaction to craft single-strand DNA probes for nanopore testing, leveraging copper's catalytic properties for signal amplification. Host-guest reaction, a noncovalent bond between molecules, specifically …

On The Use Of Cfd Modeling And Analytic Methods To Describe Pressure Drop In Highly Dense Structured Adsorbents In Gas Separation Processes And Fundamentals Of Adsorption, Ryan Timothy Sanders

Theses and Dissertations

The scope of this work can be divided into two main thrusts on topics found within adsorption. The first, and primary, topic is the use of CFD and analytical modeling to describe the flow of gas through a parallel, structured adsorbent channel which is described in Chapters 1 and 2. Chapter 1 establishes a non-experimental methodology based on using a 3D Navier-Stokes (NS) computational fluid dynamics (CFD) model in lieu of experiments, for developing 1D axial pressure drop correlations for structured adsorbents with parallel channels. Chapter 2 utilizes the methodology established in Chapter 1 in order to develop a new …

A Study Of Direct Sensitivity Method Solving Optimal Control Problems With Single And Multiple Time Grids With An Application In An Experimental Hybrid System, Hainan Wang

Theses and Dissertations

Computational methods for optimal control are important for dealing with bottlenecks in industries. By implementing optimal operation strategies obtained from the computational methods into dynamic systems, objectives such as saving energy, reducing cost, exploiting potential, and improving efficiency can be achieved. Computational methods for optimal control have been used in a broad range of disciplines, including aeronautics and astronautics, oil and chemical engineering, power systems, clean energy, biomedical engineering, economics, and management. Due to the great application value of optimal control, its computational methods have drawn worldwide attention. Direct methods are most effective in computational methods for optimal control. Direct …

Development Of Dip-Coated Carbon Fibers For Structural Power Composites And Optimization Of Bus Plates For Passively Propagation Resistant Batteries, David Petrushenko

Theses and Dissertations

Increasing demand for lithium-ion batteries in electric vehicles, portable electronics, and electric aircraft is a driving force for the expansion in new battery architectures to achieve higher gravimetric and volumetric efficiencies. In practice, maximizing energy density can be achieved by introducing state-of-the-art materials to increase the capacity of cells or by reducing the system's mass by incorporating lightweight structural materials. An alternative approach is to develop systems capable of performing multiple functions simultaneously that combine mono-functions of the battery and vehicular structure in a multifunctional component capable of storing electrical energy and providing structural support.

The initial focus of this …

Modeling Rate Dependent Volume Change In Porous Electrodes In Lithium-Ion Batteries, Taylor R. Garrick, Miguel A. Fernandez, Brian J. Koch, Erin Efimoff, Matthew Jones, Rafid Mollah, Hunter Teel, Xiaoniu Du, Sirivatch Shimpalee, Song-Yul Choe, Venkat R. Subramanian, Jason B. Siegel

Faculty Publications

Automotive manufacturers are working to improve individual cell, module, and overall pack design by increasing the performance, range, and durability, while reducing cost. One key piece to consider during the design process is the active material volume change, its linkage to the particle, electrode, and cell level volume changes, and the interplay with structural components in the rechargeable energy storage system. As the time from initial design to manufacture of electric vehicles decreases, design work needs to move to the virtual domain; therefore, a need for coupled electrochemical-mechanical models that take into account the active material volume change and the …

Advances In Electrocatalytic Dehydrogenation Of Ethylamine To Acetonitrile, Yanlin Zhu, Dezhen Wu, Jinyao Tang, Dakota Braaten, Bin Liu, Zhenmeng Peng

Faculty Publications

The electrocatalytic dehydrogenation of ethylamine (EDH), owing to its high hydrogen content, holds broad prospects in electrochemical hydrogen (H2) production, H2 storage, and addressing energy issues, thus deserving wide attention. In this feature article, we first summarized the fundamentals of thermocatalytic and electrocatalytic EDH and reviewed the recent state-of-the-art advances in catalyst research, specifically platinum group metal (PGM) catalysts and non-PGM catalysts. We systematically discussed the potential applications of electrocatalytic EDH in energy storage and conversion. Finally, we provide our perspective on the key challenges and future developments in this field. We believe this feature article will offer helpful guidance …

Machine Learning Approaches To The Exploration Of Ammonia Synthesis Catalysts Utilizing Experimental Data, Rasika Jayarathna

Theses and Dissertations

Traditional heterogeneous catalyst discovery process relies upon human expert-guided experiments based on domain knowledge and human intuition supported by catalyst characterization. However, this process is time and resource-consuming and suffers from human bias. Machine learning (ML) models trained on experimental data have the potential to significantly accelerate this discovery process by guiding experiments to optimize the catalyst performance and increase the understanding of the catalysts. Ammonia synthesis catalysts are a class of catalysts widely investigated in the literature, which has generated decades of experimental data. Moreover, ammonia has been gaining attention since it can be used as a carbon-free next-generation …

Investigation Of Ethane Dehydrogenation And Hydrogenolysis On Pt(111), Pt(211) And Pt(100): Bayesian Quantification And Correction Of Dft-Based Enthalpic And Entropic Uncertainties, Mubarak Bello

Theses and Dissertations

Computational investigations of heterogeneously catalyzed reactions using density functional theory (DFT) are often inaccurate, largely due to uncertainties in the choice of DFT functional (enthalpic uncertainty) and approximations for modeling adsorbate movement along the catalyst surface (entropic uncertainty). This work illustrates that both uncertainties are significant in the investigation of the ethane dehydrogenation (EDH) and hydrogenolysis on Pt catalysts by considering the complete deconstruction of ethane on Pt(111), Pt(211), and Pt(100) using microkinetic modeling (MKM). Hence, this work uses both non-calibrated and Bayesian calibrated MKMs to quantify and correct inaccuracies in macroscopic properties due to both uncertainties. A Bayesian approach …

Exploring Shape Dependency Of Catalysts For Chemical Reactions, Kaveh Shariati

Theses and Dissertations

Recent advancements in the synthesis of nanoparticles, particularly one-dimensional (1D) nanoparticles, have significantly enhanced the catalytic activity of various processes by enabling precise control over their morphologies and exposing unique crystallographic facets. The shape of nanoparticles is closely linked to their chemical, physical, electrical, optical, magnetic, and catalytic properties. This dissertation investigates the impact of 1D nanoparticle catalysts on two distinct and well-known chemical reactions. In the first part of the study, we explore the catalytic activity and selectivity of silver catalysts in the ethylene epoxidation reaction, which are intrinsically linked to their faceting. Silver nanowire catalysts representing Ag(100) and …

Simulation Of A Passive Osmosis-Integrated Electrolyzer For Seawater Electrolysis, Masoomeh Ghasemi

Theses and Dissertations

Efforts to develop direct seawater electrolysis technology have been ongoing due to the need for pure water in electrolysis and the abundance of seawater. However, progress has been hampered by several issues, including competition with the chlorine evolution reaction, higher membrane resistance, corrosion of electrodes, and scaling from multivalent cations [1]. To avoid these issues, our project has proposed a new reactor that integrates passive osmosis (extracting fresh water from seawater) with electrolysis. In this thesis, we will discuss the operation of the osmosis-integrated electrolyzer and show theoretical predictions of the osmotic pressure differential and water flux/velocity profiles under different …

Applications Of Catalytic Ammonia Chemistry: From Low-Pressure Ammonia Synthesis To The Decomposition Of Tritiated Ammonia As A By-Product Of Magnetically Confined Nuclear Fusion, Jennifer Kules Naglic

Theses and Dissertations

Ammonia is the 2nd most produced chemical in the world with vital importance for its use in fertilizer as the global population has grown in accordance with the industrialization of NH3. While 80% of NH3 produced goes to fertilizer, it has gained attention recently as a hydrogen storage and transportation vessel. Industrially, NH3 is produced at high temperatures and pressures which in turn require high electrical input. Turning to a green NH3 cycle with low temperature and pressure membrane reactors for both NH3 synthesis and decomposition would allow for much lower energy input as well as a renewable energy to …

Recent Progress And Perspectives Of Liquid Organic Hydrogen Carrier Electrochemistry For Energy Applications, Jinyao Tang, Rongxuan Xie, Parsa Pishva, Xiaochen Shen, Yanlin Zhu, Zhenmeng Peng

Faculty Publications

Amidst the global pursuit of clean and sustainable energy, the transition towards a hydrogen economy holds immense promise, yet is encumbered by significant storage challenges. Liquid organic hydrogen carrier (LOHC) electrochemistry emerges as a promising solution to enable efficient and sustainable hydrogen storage, meanwhile broadening the horizons of LOHCs for use as clean, renewable, and intense energy carriers to store and generate electricity. In this perspective, we embark on a review of recent trends and progress in LOHC redox electrochemistry, properties, and applications. We categorize electrochemically active, regenerable LOHCs into alcohols, amines, aromatic compounds, aminoxyl species, and others, based on …

Recent Progress And Perspectives Of Liquid Organic Hydrogen Carrier Electrochemistry For Energy Applications, Jinyao Tang, Rongxuan Xie, Parsa Pishva, Xiaochen Shen, Yanlin Zhu, Zhenmeng Peng

Faculty Publications

Amidst the global pursuit of clean and sustainable energy, the transition towards a hydrogen economy holds immense promise, yet is encumbered by significant storage challenges. Liquid organic hydrogen carrier (LOHC) electrochemistry emerges as a promising solution to enable efficient and sustainable hydrogen storage, meanwhile broadening the horizons of LOHCs for use as clean, renewable, and intense energy carriers to store and generate electricity. In this perspective, we embark on a review of recent trends and progress in LOHC redox electrochemistry, properties, and applications. We categorize electrochemically active, regenerable LOHCs into alcohols, amines, aromatic compounds, aminoxyl species, and others, based on …

Development Of An Experimentally Validated Computational Fluid Dynamics Model For A Pbi Membrane-Based Anhydrous Hcl Electrolyzer, Kris Likit-Anurak, Hunter R. Teel, Ishwor Karki, Ben I. Howard, Brian C. Benicewicz, Sirivatch Shimpalee, Benjamin H. Meekins

Faculty Publications

We report the development of an experimentally-validated computational fluid dynamics (CFD) model for simulation of an anhydrous HCl electrolyzer. The experimental data from 3 membrane variants was used to provide kinetic and membrane parameters for the model. The model not only accurately simulates overall electrolyzer performance, but it also provides key insights into the transport phenomena within the electrolyzer. The model allows simulation of experimental parameters like high HCl flowrates and increased cell pressure that pose a high safety risk to researchers. The model shows hotspots in the temperature distribution that will need to be addressed by flow field modification …

Multiscale Modeling Of Oxygen Evolution Through Generated Bilayer Porous Transport Layers For Pemwe Performance Improvement, M. Sepe, G.-H. Jung, G.S- Doo, C.-S. Lee, H.-S. Cho, N. Tippayawong, Sirivatch Shimpalee

Faculty Publications

Optimization of proton exchange membrane water electrolyzers (PEMWE) has become a focus of researchers looking for a reliable way to generate power. A vital component to PEMWE operation is the porous transport layer (PTL) on the anode side, which is where oxygen is produced. The PTL must allow water access to the catalyst layer and remove oxygen simultaneously. In this work, a previously developed imaging technique is used to generate bilayer PTL structures. A multiscale modeling approach was used to study the effect of a bilayer PTL on oxygen evolution and PEMWE performance. First, a micro scale model was used …

Polybenzimidazole Membranes For Electrochemical Applications With Harsh Operating Conditions, Kris Likit-Anurak

Theses and Dissertations

Polybenzimidazole (PBI) membranes are high temperature proton exchange membranes (PEMs) which have advantages such as being able to operate in high temperatures, strong acid environments, and have no need for external humidity during operation. PBI membranes have been demonstrated to work effectively in multiple electrochemical devices, including fuel cells, hydrogen separation pumps, redox flow batteries, and a hybrid sulfur electrolyzer. In this work, para-PBI and densified para-PBI membrane have been used to improve electrochemical performance in harsh operating conditions that are both high temperature (≥120 ̊C) and high acid concentration (≥ 5M). First, we demonstrated the use of para-PBI membranes …

Understanding The Corrosion And Discharge Behaviour Of Zinc Anodes In Primary Alkaline Batteries, Brian James Lenhart

Theses and Dissertations

Primary zinc alkaline batteries power a wide array of everyday use electronic devices such as remote controls, calculators, cameras, and flashlights and will own an appreciable share of the battery market for the foreseeable future. Primary alkaline batteries generally utilize carbon, gas diffusion air, or manganese dioxide cathode but always coupled with a slurry zinc anode. There are several issues with this primary alkaline platform, largely emphasized by the performance of the zinc anode, such as a gassing phenomenon which leads to battery rupture and under certain circumstances, low material utilization leading to low energy density. The gassing and material …

Engineering Hybrid Colloidal Systems Formed By Charge-Driven Assembly Between Spherical Soft Nanoparticles And Discotic Nanoplatelets, Gelareh Rezvan

Theses and Dissertations

Soft matter, a fascinating class of materials, holds a paramount significance in the realm of material design and engineering. Within this broad category, colloidal gels with their unique characteristics have drawn tremendous attention in a variety of applications, spanning from biomedical engineering to oil and gas recovery. Meeting the specific requirements and criteria of these diverse fields necessitates the development of colloidal gels with highly tunable properties to optimize their performance for a wide range of applications. Hence, both scientific and industrial advancement call for more control over the gel properties by exploring novel practical parameters. This dissertation describes an …

Heterogeneous Catalyst Design For Biomass Conversion, Dia Sahsah

Theses and Dissertations

Catalytic upgrading of bio-based feedstocks to commodity chemicals and fuels is pivotal to a more sustainable, renewable, and environmentally benign chemical economy. However, due to the high oxygen content, high water solubility, excessive reactivity, and thermal instability, typical and well-developed catalytic material and reactor processes reliably utilized in conventional petrochemical industry are, in general, not suitable for the processing of biomass feedstocks. Therefore, the development of novel heterogeneous catalysts is necessary in order to design new high-performance catalytic reactor systems. However, rational catalyst design is a multifaceted problem, and a myriad of factors influencing the catalytic performance at the reactor …

Structure Property Performance Of Ti3c2 Mxene/Polyelectrolyte Hybrids For Electronic And Electromagnetic Applications, Farivash Gholamirad

Theses and Dissertations

Hybrid materials based on transition metal carbide MXene (Ti3C2Tx) nanosheets have great potential for electronic, electromagnetic interference (EMI) shielding, and environmental applications due to the unique combination of considerable electrical conductivity of 4000 to 15000 S.cm-1, abundant surface functional groups (OH, O, F, Cl), and suitable mechanical properties. However, the performance of final products depends not only on the properties of constituent components but also on the morphology of the assembly. The strong repulsive electrical double layer forces among MXene nanosheets make control over their assembly morphology and final properties challenging. To address this challenge, this dissertation focuses on applying …

Catalytic Hydrogenation Of Dimethyl Oxalate To Ethylene Glycol Using Silver Based Catalysts On Sba-15, Nicolas Edouard Gleason-Boure

Theses and Dissertations

Ethylene glycol (EG) is an important industrial chemical in the manufacturing of certain plastics. There is growing industrial interest in the production of dimethyl oxalate (DMO) from syngas, which can be hydrogenated to produce EG. Many studies have focused on the catalytic reduction of DMO using copper-based catalysts on silica supports, but fewer studies have been done on the effects of silver for this reaction. This work presents an in-depth study of silver catalysts prepared via various methods including incipient wetness impregnation, charge enhanced dry impregnation, and the use of various organic solvents. Reaction studies show that using pure methanol …

Insights Into Supported Metal Catalyst Sintering And Their Application For Bio-Oil And Crude Oil Upgradation, Md Fakhruddin Patwary

Theses and Dissertations

Typical heterogeneous catalysts consist of transition metal nanoparticles anchored against sintering on an inert, porous, high temperature stable support. The synthesis of supported catalyst involves pretreatment (drying, reduction) of deposited, ionic metal precursor complexes to form metal nanoparticles. In the first part of this work, we aim to understand the influence of pretreatment (reduction temperature, heating rate, moisture content) on final particle size. Supported nanoparticles of Pt and Pd were synthesized by strong electrostatic adsorption (SEA) and dry impregnation (DI). Reduced samples were characterized by in-situ and ex-situ XRD and STEM. The DI-derived samples generally showed an expected increase of …

First Principles Doping Analysis Of Perovskite- And Ruddlesden-Popper-Based Solid Oxide Fuel Cells, Nicholas Alexander Szaro

Theses and Dissertations

Solid oxide fuel cells (SOFCs) have shown significant promise as a high efficiency energy conversion technology. SOFCs are solid-state, high temperature (600 – 1000 °C), and electrochemical conversion devices that can operate with a wide variety of fuels such as hydrogen, syngas, and hydrocarbon feedstocks. The state-of-the-art SOFC is manufactured with a lanthanum strontium manganite (LSM) cathode, an yttria-stabilizedzirconia electrolyte (YSZ), and a nickel on yttria-stabilized-zirconia (Ni/YSZ) cermet anode. LSM || YSZ || Ni/YSZ SOFCs operate at or above 800 °C to achieve sufficient oxide mobility. The high temperatures introduce problems such as long device start-up, particle sintering, and material …

Revisiting The Volumetric Swing Frequency Response Method For The Determination Of Limiting Mass Transfer Mechanisms Of N2 And O2 In Carbon Molecular Sieve 3k172, Adam Marshall Burke

Theses and Dissertations

Adsorption-based separations processes, along with the adsorbents that enable them, have benefited from a greater particular focus in recent years, following a desire to improve process energy efficiencies and cost economics. One such adsorbent, carbon molecular sieves (CMS), have likewise been a greater focus. CMS materials offer several key practical uses, such as the separation of nitrogen and oxygen, and the removal of carbon dioxide from methane process streams. In order to effectively design and implement an industrial scale process using a CMS material, the behavior of these gases on the chosen material must be known, including the limiting mass …