Physical Chemistry Commons^™

Performance Of Co2/H2O Co-Electrolysis In A Flat-Tube Solid Oxide Electrolysis Cell Stack Under Air-Free Environment, Xiao-Hui Zhong, Fei Wang, An-Qi Wu, Bei-Bei Han, Jian-Xin Wang, Wan-Bing Guan

Journal of Electrochemistry

This work investigates the transient performance and stability of CO₂/H₂O co-electrolysis in an air-free environment using a flat-tube solid oxide electrolysis cell (SOEC) stack. The results show that the transient behavior of the stack with and without blowing gas in the air electrode is almost the same. With a current density of 0.67 A·cm⁻²@750 °C, the stack operated for over 200 h under co-electrolysis conditions with no air blowing, and the voltage drop rate of the stack was approximately 0.203%/100 hours. Microstructure analysis reveals significant loss of Ni particles and formation of an insulating …

The Delocalized Toolbox: Tuning Strain, Energetic And Optoelectronic Properties Of Aryl Heterocyclic Scaffolds For Application-Driven Endeavors, Michael Josef Holzmann

Chemistry and Chemical Biology ETDs

This is a three-part dissertation. Part 1 is composed of chapters 1-3 which revolves around the optimization of cyclononyne reactivity towards 1,3 dipolar cycloadditions. Specifically, the synthesis and reactivity of sulfate, sulfamate and sulfamide-bearing cyclononynes will be discussed. Chapters 4-5 comprise Part 2 which addresses optimization of ruthenium olefin metathesis towards reversible activation and inhibition. The mechanism of reversible inhibition mediated by a hexaarylbiimidazole photo-inhibitor will be elucidated. Part 3 consists of chapters 6-8 which describes structure-functional relationship studies on carbon dots and harnessing that insight for sensing applications. Data relating to assays performed with explosive analytes will be analyzed …

Predicting PkA Of Flexible Polybasic Tetra-Aza Macrocycles, Tatum K. Harvey, Kristof Pota, Magy Mekhail, David M. Freire, Donatus A. Agbaglo, Benjamin G. Janesko, Kayla N. Green

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We present physics-based pK_a predictions for a library of tetra-aza macrocycles. These flexible, polybasic molecules exhibit highly charged states and substantial prototropic tautomerism, presenting a challenge for pK_a prediction. Our computational protocol combines CREST/xTB conformational sampling, density functional theory (DFT) refinement in continuum solvent, and a linear empirical correction (LEC). This approach predicts known tetra-aza macrocycle pK_a to within a root-mean-square deviation 1.2 log units. This approach also provides reasonable predictions for the most stable protomers at different pH. We use this protocol to predict pK_a values for four novel, synthetically achievable, …

An Open-Framework Iron-Selenite As Cathode For Li- Ion Batteries, Sutapa Bhattacharya, Aleksandr V. Chernatynskiy, Amitava Choudhury

Miners Solving for Tomorrow Research Conference

No abstract provided.

The Effect Of Nanomorphology As Quantified Via The K‑Index On The Drug Delivery Properties Of Isocyanate-Derived Aerogels, Stephen Y. Owusu, A. B. M. Shaheen Ud Doulah, Vaibhav A. Edlabadkar, Kamden J. George, Chariklia Sotiriou-Leventis

Miners Solving for Tomorrow Research Conference

No abstract provided.

Advanced Mathematical And Computational Methods In Quantum Chemistry, Chao Yin

Chemistry Theses and Dissertations

Wave-function based ab initio calculation methods have been gaining significant atten- tion from chemists due to their ability to provide insights into experimental results. However, their application to large systems is limited by the considerable computational cost involved, especially when dealing with high-dimensional tensors inherent to these calculations. To address these challenges, two primary strategies have been explored in this study. First, advancements in hardware architecture and algorithmic development. Graphics Processing Units (GPUs) have facilitated parallel computation, leading to a significant acceleration of these calculations. In this work, we propose a method for evaluating two-electron repulsion integrals (ERIs)—a key component …

Mechanochemical Reaction Kinetics—A Theoretical Modeling And Experimental Study, Maria Dolores Masso Ramirez

Mechanical & Aerospace Engineering Theses & Dissertations

Mechanochemical reactions represent a class of chemical processes triggered by mechanical energy, widely recognized for their efficiency, solvent-free nature, and environmental benefits. They are increasingly applied in synthetic chemistry, a branch of science focused on creating new chemical compounds through controlled laboratory reactions. However, the mechanisms underlying mechanical activation remain poorly understood, primarily due to the difficulty in quantifying energy transfer during milling, where solid reactants are ground together using a ball mill. This thesis aims to bridge the gap in understanding the relationship between mechanical parameters and reaction kinetics by developing and validating a theoretical framework based on dimensional …

Quantum Effects In Collisional Energy Transfer Simulated Using Mixed Quantum/Classical Theory, Dulat Bostan

Dissertations (1934 -)

Mixed quantum/classical theory (MQCT) was used to study collisional energy transfer between the rotational states of molecules with the focus on reproducing quantum effects related to this process. Namely, rotational energy transfer in the N₂ + O system was studied to replicate quantum interference effects observed as oscillations of scattering cross section as a function of collision energy. Both MQCT code and the full-quantum code MOLSCAT were used for calculations, and results were in excellent agreement with the experiment and the full-quantum infinite-order sudden method from literature. The CO + CO system was used as a case study for …

Experimental And Computational Investigation Of Ethylene Oxide Hydrate And Its Mixed Hydrates With Propane And Isobutane, Adebayo Paul Adeleye

Master's Theses (2009 -)

Gas hydrates represent an important class of crystalline solids, where water molecules form cage-like frameworks that encapsulate gas molecules. They have garnered significant attention for their unique properties and diverse applications in energy and environmental science. This study investigates the formation and vibrational properties of the ethylene oxide (EO) hydrate (structure I, sI) and EO-seeded hydrates of propane and isobutane (structure II, sII) using matrix isolation Fourier-transform infrared (FTIR) spectroscopy, supported by Density Functional Theory (DFT) calculations at the B3LYP/6-311++G(d,p) level of theory. Under low-temperature and low-pressure conditions, EO hydrate was formed by co-depositing a premix of EO and argon …

Study On Dopamine Electrochemical Sensing Based On Au@Mos2, Ning An, Ni Su, Xin-Ran Li, Jian-Yu Liu, Qi-Yan Wang

Journal of Electrochemistry

Dopamine (DA) is a vital neurotransmitter, and accurate detection of its concentration is critical for both clinical diagnostics and neuroscience research. Due to its electrochemical activity, DA is commonly detected using electrochemical methods, which are favored for their simplicity, fast response time, and suitability for in vivo analysis. In this work, a highly sensitive DA electrochemical sensor was developed using an Au@MoS₂ composite, created by modifying molybdenum disulfide (MoS₂) nanosheets with gold nanoparticles through HAuCl₄ reduction, and it was aimed at enhancing DA adsorption and improving detection performance. Scanning Electron Microscopy (SEM), transmission electron microscopy (TEM), …

Recent Advances In Non-Enzymatic Electrochemical Sensors For Theophylline Detection, Gustria Ernis, Yulia M T A Putri, Muhammad Iqbal Syauqi, Prastika Krisma Jiwanti, Yeni Wahyuni Hartati, Takeshi Kondo, Qonita Kurnia Anjani, Jarnuzi Gunlazuardi

Journal of Electrochemistry

Detection of target analytes at low concentrations is significant in various fields, including pharmaceuticals, healthcare, and environmental protection. Theophylline (TP), a natural alkaloid used as a bronchodilator to treat respiratory disorders such as asthma, bronchitis, and emphysema, has a narrow therapeutic window with a safe plasma concentration ranging from 55.5–111.0 μmol·L^–1 in adults. Accurate monitoring of TP levels is essential because too low or too high can cause serious side effects. In this regard, non-enzymatic electrochemical sensors offer a practical solution with rapidity, portability, and high sensitivity. This article aims to provide a comprehensive review of the recent developments …

In-Situ Electrodeposition Of Feco-Mof On Au Ultramicroelectrode For Highly Sensitive Detection Of Epinephrine, Yan Chen, Shang Jian, Si-Yu Wan, Xiao-Tong Cui, Zhong-Gang Liu, Zheng Guo

Journal of Electrochemistry

Metal-organic framework (MOF) nanostructures have emerged as a prominent class of materials in the advancement of electrochemical sensors. The rational design of bimetallic MOF-functionalized microelectrode is of importance for improving the electrochemical performance but still in great challenge. In this work, the bimetallic FeCo-MOF nanostructures were assembled onto a gold disk ultramicroelectrode (Au UME, 5.2 μm in diameter) via an in-situ electrodeposition method, which enhanced the sensitive detection of epinephrine (EP). The in-situ electrodeposited FeCo-MOF exhibited a characteristic nanoflower-like morphology and was uniformly dispersed on the Au UME. The FeCo-MOF/Au UME demonstrated excellent electrochemical performance on the detection of EP …

Facile Synthesis Of Tetraaryl Phosphonium Ionic Liquids, Stephanie C. Jones, Devin J. Schwaibold, Grant Meadows, Brennan Shuler, Richard E. Sykora, Frank Rolf Fronczék, James H. Davis, Benjamin Wicker

EKU Faculty and Staff Scholarship

The syntheses of triphenyl-2-pyridylphosphonium salts, [Mopyphos]A, where A-= BF4-, B(C6H5)4-, (CF3SO2)2N-, Sac-, and Ace-. (Sac-= saccharinate, Ace-= acesulfamate) are described. These salts can be synthesized on a multi-gram scale with good yields and have been characterized by NMR, single crystal XRD, and HRMS. Thermal analyses indicate that the bistriflimide (Tf2N-= (CF3SO2)2N-) salts are especially amenable towards high-temperature ionic liquid (IL) applications with decomposition temperatures above 450 degrees C. The synthetic methods described herein can be utilized to generate several phosphonium bistriflimide ILs of the general formula [(C6H5)3P-Ar]Tf2N, where Ar = N-heteroaryl).

Effect Of Pre-Adsorbed Species On High-Pressure Adsorption Of Methane In Zeolite 5a Using Grand Canonical Monte Carlo (Gcmc) Simulations, Kanhamardi Lao, Brooks D. Rabideau

Shelby Hall Graduate Research Forum Posters

Natural gas upgrading, which removes impurities from methane (CH4), is essential for industrial applications, including liquefied natural gas (LNG) production and power generation, as well as for residential use. Removing non-hydrocarbon impurities such as carbon dioxide (CO2), nitrogen (N2), and water vapor (H2O), among others, along with separating heavier hydrocarbon gases from raw natural gas, is required to achieve high- purity methane and prevent pipeline corrosion. Zeolite 5A is a microporous aluminosilicate material with a pore size of approximately 5 Å, containing sodium and calcium cations that balance the framework’s negative charge. Its structure offers high thermal stability and a …

Metal Nitrides As Cathode Hosts For Lithium-Sulfur Batteries, Hai-Ji Xiong, Cheng-Wei Zhu, Ding-Rong Deng, Qi-Hui Wu

Journal of Electrochemistry

Lithium-sulfur batteries are considered as one of the potential solutions as integrating renewable energy systems for large-scale energy storage because of their high theoretical energy density (2600 Wh·kg^–1) and specific capacity (1675 mAh·g^–1). Currently, various strategies have been proposed to overcome the technical barriers, e.g., “shuttle effect”, capacity decay and volumetric change, which impede the successful commercialization of lithium-sulfur batteries. This paper reviews the applications of metal nitrides as the cathode hosts for high-performance lithium-sulfur batteries, summarizes the design strategies of different host materials, and discusses the relationship between the properties of metal nitrides and their …

Enhancing Cycle Life Of Graphite ‖ Lifepo4 Batteries Via Copper Substituted Li2Ni1-XCuXO2 Cathode Prelithiation Additive, Jian-Ming Zheng, Jing-Wen Zhang, Tian-Peng Jiao

Journal of Electrochemistry

Lithium nickel oxide (Li₂NiO₂), as a sacrificial cathode prelithiation additive, has been used to compensate for the lithium loss for improving the lifespan of lithium-ion batteries (LIBs). However, high-cost Li₂NiO₂ suffers from inferior delithiation kinetics during the first cycle. Herein, we investigate the effects of the cost-effective Cu substitution of Li₂Ni_1-xCu_xO₂ (x = 0, 0.2, 0.3, 0.5, 0.7) synthesized by high-temperature solid-phase method on the structure, morphology, electrochemical performance of graphite‖LiFePO₄ battery. The X-ray Diffraction (XRD) refinement result demonstrates that Cu substitution strategy is favorable …

Sno2 Particles Embedded Into Carbon Coated Mesoporous SioX Rod As High Volumetric Capacity Anode For Lithium-Ion Batteries, Jia-Lin Guo, Ni-Ni Li, Peng Zheng

Journal of Electrochemistry

Due to the high capacity and moderate volume expansion of silicon protoxide SiO_x (160%) compared with that of Si (300%), reducing silicon dioxide SiO₂ into SiO_x while maintaining its special nano-morphology makes it attractive as an anode of Li-ion batteries. Herein, through a one-pot facile high-temperature annealing route, using SBA15 as the silicon source, and embedding tin dioxide SnO₂ particles into carbon coated SiO_x, the mesoporous SiO_x-SnO₂@C rod composite was prepared and tested as the anode material. The results revealed that the SnO₂ particles were distributed uniformly in the …

Epr Imaging Workshop: From Theory And Practice To Applications, Arthur H. Heiss, Ralph T. Weber, Sandra S. Eaton, Gareth R. Eaton

TeachEPR Submissions

Methods of imaging and insights from imaging are described. Practical aspects of sample type and dimensions are described.

Workshop presented at the 27th International EPR Symposium, sponsored by Bruker BioSpin EPR Division and the University of Denver, in Denver, Colorado on August 1, 2004.

Workshop On The Epr Of Aqueous Samples, Gareth R. Eaton

TeachEPR Submissions

The problem with water and other materials that absorb microwave energy are described. Dielectric properties are described as a function of frequency.

Workshop presented at the 25th International EPR Symposium on July 28, 2002.

Special Purpose Epr Resonators, Gareth R. Eaton

TeachEPR Submissions

Many types of EPR resonators are described.

Special applications that use various resonators are mentioned.