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Full-Text Articles in Catalysis and Reaction Engineering

Influence Of Synthesis Conditions On The Physicochemical And Electrocatalytic Properties Of Non-Stoichiometric Ba2sr2la2ti4o12 Perovskites, Ofeliya Kostadinova, Iliyan Popov, Simeon M. Stankov, Hristo Kolev, Tamara Petkov Jan 2023

Influence Of Synthesis Conditions On The Physicochemical And Electrocatalytic Properties Of Non-Stoichiometric Ba2sr2la2ti4o12 Perovskites, Ofeliya Kostadinova, Iliyan Popov, Simeon M. Stankov, Hristo Kolev, Tamara Petkov

Karbala International Journal of Modern Science

Present work studies the influence of the pretreatment milling media (deionized water (BLTOS-H) and isopropanol (BLTOS-i)) on the surface characteristics, structure, chemical composition and catalytic activity of non-stoichiometric Ba2Sr2La2Ti4O12 perovskites. The IR spectroscopy and XRD analyses shows a difference in the structure and phase composition of the two materials. X-ray photoelectron spectroscopy detects a Ba2+- and La3+-enriched and Sr2+-depleted surface. The BLTOS-i sample appears to exhibit higher specific surface area (SSA) and pore volume in comparison to BLTOS-H. The electrochemical tests showed that BLTOS-H sample have similar behavior to platinum at current densi-ties up to 10 mA cm-2, while BLTOS-i …


Running Shoe Pedometer, Benjamin Kasper Jan 2023

Running Shoe Pedometer, Benjamin Kasper

Williams Honors College, Honors Research Projects

Running shoe pedometer aims to solve the issue of worn out running shoes. It can be difficult to know just how many miles you have run in your shoes and when a new pair is needed. Running in old shoes and worn out shoes is heavily linked to injury. My proposed project is a device that is powered by the compressive forces on the shoes soles that counts the number of steps the wearer takes using a microcontroller. Then, when the shoe reaches milestone that indicate it has been used 75% 90% and 100% of its expected life, it will …


Advances On Composite Cathodes For Lithium-Sulfur Batteries, Xi-Yao Li, Chang-Xin Zhao, Bo-Quan Li, Jia-Qi Huang, Qiang Zhang Dec 2022

Advances On Composite Cathodes For Lithium-Sulfur Batteries, Xi-Yao Li, Chang-Xin Zhao, Bo-Quan Li, Jia-Qi Huang, Qiang Zhang

Journal of Electrochemistry

Lithium-sulfur (Li-S) batteries are deemed as high-promising next-generation energy storage technique due to their ultrahigh theoretical energy density, where the sulfur cathodes with high specific capacity guarantee the energy density advantage and directly determine the battery performances. After decades of exploration, the most promising sulfur cathodes are sulfur/carbon composite (S/C) cathodes and sulfurized polyacrylonitrile (SPAN) cathodes. In this manuscript, recent advances on S/C and SPAN cathodes in Li-S batteries are comprehensively reviewed. The electrochemical reaction circumstances on S/C and SPAN cathodes are firstly introduced and compared to reveal the working mechanisms of the two types of Li-S batteries. The S/C …


Synthesis Of Novel Chiral Phosphorothioic Acid Organocatalysts And Application To Synthetic Methodology, Parsa Azaei Dec 2022

Synthesis Of Novel Chiral Phosphorothioic Acid Organocatalysts And Application To Synthetic Methodology, Parsa Azaei

Undergraduate Research Symposium Posters

Much research efforts have been centered towards the synthesis of novel Bronsted acid catalysts. These organocatalyst enable synthesis of natural products, pharmaceuticals, and bioactive small molecules under toxic-metal-free conditions by donating their protons, while not being consumed in the reaction. Chiral phosphorothioic acid have significant potential as novel organocatalysts due to their high modifiability of chirality and acidity under environmentally friendly conditions; however, synthesis of these organocatalysts are far and in between. Therefore, our research aimed to i) synthesize novel phosphorothioic acid organocatalysts and ii) to apply these novel catalysts toward new methodology development.


Carbon-Al Interface Effect On The Performance Of Ionic Liquid-Based Supercapacitor At 3 V And 65 OC, Zhen-Zhen Ye, Shu-Ting Zhang, Xin-Qi Chen, Jin Wang, Ying Jin, Chao-Jie Cui, Lei Zhang, Lu-Ming Qian, Gang Zhang, Wei-Zhong Qian Dec 2022

Carbon-Al Interface Effect On The Performance Of Ionic Liquid-Based Supercapacitor At 3 V And 65 OC, Zhen-Zhen Ye, Shu-Ting Zhang, Xin-Qi Chen, Jin Wang, Ying Jin, Chao-Jie Cui, Lei Zhang, Lu-Ming Qian, Gang Zhang, Wei-Zhong Qian

Journal of Electrochemistry

Ionic liquid (IL) electrolyte-based supercapacitors (SCs) have advantages of high operating voltage window, high energy density and nonflammability, as compared to conventional acetonitrile-based organic electrolyte SCs, and are typically suitable for the large-scale energy storage in the era of carbon neutrality full of renewable, but unstable electricity. However, current efforts were concentrated on the study with coin-cell type of IL-SCs, and less has been reported on the pouch type of IL-SCs for a long cycling time yet. To fabricate a reliable SC for the life time test or for the accelerated aging test under high temperature, one should concern the …


Elucidation Of Active Site And Mechanism Of Metal Catalysts Supported In Nu-1000, Hafeera Shabbir Dec 2022

Elucidation Of Active Site And Mechanism Of Metal Catalysts Supported In Nu-1000, Hafeera Shabbir

All Dissertations

Advances in extraction of shale oil and gas has increased the production of geographically stranded natural gas (primarily consisting of methane (C1) and ethane (C2)) that is burned on site. A potential utilization strategy for shale gas is to convert it into fuel range hydrocarbons by catalytic dehydrogenation followed by oligomerization by direct efficient catalysts. This work focuses on understanding metal cation catalysts supported on metal-organic framework (MOF) NU-1000 that will actively and selectively do this transformation under mild reaction conditions, while remaining stable to deactivation (via metal agglomeration or sintering). I built computational models validated by experimental methods to …


Multi-Electron Reaction-Boosted High Energy Density Batteries: Material And System Innovation, Rui-Qi Guo, Feng Wu, Xin-Ran Wang, Ying Bai, Chuan Wu Nov 2022

Multi-Electron Reaction-Boosted High Energy Density Batteries: Material And System Innovation, Rui-Qi Guo, Feng Wu, Xin-Ran Wang, Ying Bai, Chuan Wu

Journal of Electrochemistry

The continuous development of the global energy structure transformation has put forward higher demands upon the development of batteries. The improvements of the energy density have become one of the important indicators and hot topic for novel secondary batteries. The energy density of existing lithium-ion battery has encountered a bottleneck due to the limitations of material and systems. Herein, this paper introduces the concept and development of multi-electron reaction materials over the past twenty years. Guided by the multi-electron reaction, light weight electrode and multi-ion effect, current development strategies and future trends of high-energy-density batteries are highlighted from the perspective …


Application Of Artificial Intelligence To Lithium-Ion Battery Research And Development, Zhen-Wei Zhu, Jing-Yi Qiu, Li Wang, Gao-Ping Cao, Xiang-Ming He, Jing Wang, Hao Zhang Nov 2022

Application Of Artificial Intelligence To Lithium-Ion Battery Research And Development, Zhen-Wei Zhu, Jing-Yi Qiu, Li Wang, Gao-Ping Cao, Xiang-Ming He, Jing Wang, Hao Zhang

Journal of Electrochemistry

Lithium-ion batteries (LIBs) have become one of the best solutions to the energy storage issue in modern society. However, the battery materials and device development are both complex, and involve multivariable problems. Traditional trial-and-error approach, which relies on researchers to conduct experiments, has encountered bottlenecks in the improvement of the battery performance. Artificial intelligence (AI) is the most potential technology to deal with this issue due to its powerful high-speed and capabilities of processing massive data. In particular, the capability of machine learning (ML) algorithms in assessing multidimensional data variables and discovering patterns in the sets are expected to assist …


Preparation Of Highly-Cyclized Sulfurized Polyacrylonitrile For Lithium-Sulfur Batteries, Xuan Ji, Jia-Yu Wang, An-Bang Wang, Wei-Kun Wang, Ming Yao, Ya-Qin Huang Nov 2022

Preparation Of Highly-Cyclized Sulfurized Polyacrylonitrile For Lithium-Sulfur Batteries, Xuan Ji, Jia-Yu Wang, An-Bang Wang, Wei-Kun Wang, Ming Yao, Ya-Qin Huang

Journal of Electrochemistry

Sulfurized polyacrylonitrile (SPAN) is regarded as an attractive cathode candidate of lithium-sulfur (Li-S) batteries for its non-dissolution mechanism and effective alleviation of polysulfides shuttling issue in Li-S batteries, displaying high utilization of cathode active material, outstanding cycle stability and structural stability. However, the relation between cyclization degree and cycle stability of SPAN is still unveiled. In this work, SPAN-C-V composites were synthesized by co-introduction of CuSO4 and zinc n-ethyl-n-phenyldithiocarbamate (ZDB) in the co-heating of sulfur and polyacrylonitrile. The co-introduction of CuSO4 and ZDB reduced the cyclization reaction onset temperature of PAN while increased the C—C/C=C …


Modeling Solvent Extraction Of Lignin From Hardwoods, Su Pan Aug 2022

Modeling Solvent Extraction Of Lignin From Hardwoods, Su Pan

McKelvey School of Engineering Theses & Dissertations

This study interprets the observed behavior of solvent extraction of lignin from hardwoods by adapting the framework of the FLASHCHAIN theory (Niksa and Kerstein, 1991; Niksa, 2017). A constitution submodel specifies distributions of molecular weight and reactive sites for native lignin. The model simulates delignification as depolymerization of lignin macromolecules into fragments small enough to be soluble. This process competes with intrachain condensation that consumes labile bridges without forming new fragments, and with recombination that forms larger chains and inhibits further depolymerization. After the soluble fragments are transported from the particle into the bulk solvent, all chemistry continues as long …


Intersections Of Environmentalism, Chemistry, And Racism: An Experimental Study Of Halobenzene Hydrogenolysis And Critical Communication Studies Of Equitable Learning Practices Rooted In Black Feminism, Lauren O. Babb Aug 2022

Intersections Of Environmentalism, Chemistry, And Racism: An Experimental Study Of Halobenzene Hydrogenolysis And Critical Communication Studies Of Equitable Learning Practices Rooted In Black Feminism, Lauren O. Babb

Electronic Theses and Dissertations

Increasing concentrations of fluorinated aromatic compounds in surface water, groundwater, and soil pose threats to the environment. Fundamental studies that elucidate mechanisms of dehalogenation for C-X compounds (where X represents a halide) are required to develop effective remediation strategies. For halogenated benzenes, previously published research has suggested that the strength of the C-X bond is not rate-determining in the overall rate of dehalogenation. Instead, the rate-determining step has been hypothesized to be adsorption of the C-X compound onto the surface of a catalyst. Building on this hypothesis, in this work, we examine the reaction kinetics of fluorobenzene conversion to benzene, …


Wind Tunnel Modeling Of Jack Rabbit Ii Mock Urban Environment Gas Concentration Measurements, Sami S. Fares Aug 2022

Wind Tunnel Modeling Of Jack Rabbit Ii Mock Urban Environment Gas Concentration Measurements, Sami S. Fares

Graduate Theses and Dissertations

The 2015 Jack Rabbit (JR) II field trials were conducted to improve understanding of the denser-than-air dispersion of chlorine in an urban environment. The field study involved five large-scale, outdoor release trials of chlorine in a mock urban environment (MUE) at Dugway Proving Ground (DPG). Various instrumentation was deployed, including JazTM Ultraviolet-Visible (UV-Vis) point sensors capable of measuring gas-phase chlorine concentration throughout the mock urban array.

The Chemical Hazards Research Center (CHRC) was tasked by the Chemical Security Analysis Center (CSAC) with the Mock Urban Wind Tunnel (MUWT) program to study the 2015 JR II Trials at wind tunnel scale. …


Performance And Fouling During Bioreactor Harvesting, Da Zhang Aug 2022

Performance And Fouling During Bioreactor Harvesting, Da Zhang

Graduate Theses and Dissertations

Tangential flow filtration has many advantages for bioreactor harvesting as the permeate could be introduced directly to the subsequent capture step, the process is easy to scale up, and fouling of the filter is limited by the cross flow. However, membrane fouling has limited its widespread use. This is particularly problematic given the high cell densities encountered today. Here a reverse asymmetric commercial membrane, BioOptimal™ MF-SL (Asahi Kasei), where the more open surface faces the feed stream, and the tighter barrier layer faces the permeate stream, has been investigated for bioreactor harvesting. The open surface contains pores up to 40 …


Chromatographic Dynamic Chemisorption, Shreya Thakkar Jun 2022

Chromatographic Dynamic Chemisorption, Shreya Thakkar

Masters Theses

Reaction rates of catalytic cycles over supported metal catalysts are normalized by the exposed metal atoms on the catalyst surface, reported as site time yields which provide a rigorous standard to compare distinct metal surfaces. Defined as the fraction of exposed metal surface atoms to the total number of metal atoms, it is important to measure the dispersion of supported metal catalysts to report standardized rates for kinetic investigations. Multiple characterization techniques such as electron microscopy, spectroscopy and chemisorption are exploited for catalyst dispersion measurements. While effective, electron microscopy and spectroscopy are not readily accessible due to cost and maintenance …


Photocatalytic Degradation Of Organic Contaminants By Titania Particles Produced By Flame Spray Pyrolysis, Noah Babik May 2022

Photocatalytic Degradation Of Organic Contaminants By Titania Particles Produced By Flame Spray Pyrolysis, Noah Babik

Theses and Dissertations

Advanced oxidation of organic pollutants with TiO2 photocatalysts is limited due to the wide bandgap of TiO2, 3.2 eV, which requires ultraviolet (UV) radiation. When nanosized TiO2 is modified by carbon doping, charge recombination is inhibited and the bandgap is narrowed, allowing for efficient photodegradation under visible light. Here, we propose a flame spray pyrolysis (FSP) technique to create TiO2. The facile process of FSP has been successful in preparing highly crystalline TiO2 nanoparticles. Using the same procedure to deposit TiO2 onto biochar, the photocatalyst was doped by the carbonaceous material. The morphology, crystalline and electronic structure of the FSP …


Optimization Of Styrene From Ethylbenzene Case Study, Jabria Daria Thompson May 2022

Optimization Of Styrene From Ethylbenzene Case Study, Jabria Daria Thompson

Honors Theses

The following pages detail the optimization process of styrene from ethylbenzene in the Styrene Production Plant, Unit 500. There were two parts of the assignment, each with slightly different end goals. The goal of the first part of the assignment, was to create a process that would effectively and efficiently increase the negative Net Present Value (NPV) of the production plant. Procedures taken in this process included developing a working kinetic process simulation model and optimizing this model through unit operations and heat integration, as well as developing an accurate economic model that will be used to evaluate the proposed …


Kinetics Of Carboxymethylation Reaction Of Cellulose Samples With Different Degree Of Crystallinity, Ilkhom Goyibnazarov, Sherzod Yuldoshov, Abdushukhur Sarimsokov May 2022

Kinetics Of Carboxymethylation Reaction Of Cellulose Samples With Different Degree Of Crystallinity, Ilkhom Goyibnazarov, Sherzod Yuldoshov, Abdushukhur Sarimsokov

CHEMISTRY AND CHEMICAL ENGINEERING

No abstract provided.


Mathematical Modeling Of Synthesis 4´,4´´-Di-(1-Methyl-1-Hydroxy-2-Phenylethynyl)-Dibenzo-18-Crown-6, Lyubov Kozinskaya, Dilorom Mirkhamitova May 2022

Mathematical Modeling Of Synthesis 4´,4´´-Di-(1-Methyl-1-Hydroxy-2-Phenylethynyl)-Dibenzo-18-Crown-6, Lyubov Kozinskaya, Dilorom Mirkhamitova

CHEMISTRY AND CHEMICAL ENGINEERING

The main goal of this study is the mathematical modeling of the optimal conditions for the synthesis of 4´,4´´-di-(1-methyl-1-hydroxy-2-phenylethynyl)-dibenzo-18-crown-6 by the least squares method. In the STAT program, iconograms of mathematical modeling of the synthesis and the dependence of the rate of formation of 4´,4´´-di-(1-methyl-1-hydroxy-2-phenylethynyl)-dibenzo-18-crown-6 on temperature and reaction time were obtained, the corresponding analytical dependencies are determined. Mathematical processing of the results of the synthesis of 4´,4´´-di-(1-methyl-1-hydroxy-2-phenylethynyl)-dibenzo-18-crown-6 was carried out, a system of linear equations was compiled using the matrix method. The average reaction rate and the optimum of the mathematical model were determined, and the experimental and calculated …


Optimization Of A Fluidized Bed Reactor For The Production Of Styrene From Ethylbenzene, Gregory Espenan May 2022

Optimization Of A Fluidized Bed Reactor For The Production Of Styrene From Ethylbenzene, Gregory Espenan

Honors Theses

In order to optimize Unit 500, a styrene production plant, the Net Present Value (NPV) was used as the objective function to ensure every optimization strategy had a positive economic effect. To optimize a chemical plant, it is important to note efficiency, economics, product specifications, and production requirements. The goal of this project was to make changes to the base case of Unit 500 to minimize the cost to produce styrene for an upstream unit. PRO/II was used to simulate various points in different unit operations throughout the process. The NPV was measured after each unit operation was simulated to …


Analyzing The Surface Chemistry Of Ni-Fe Hydroxide Alloy Nanoparticles As Catalysts For The Oxygen Evolution Reaction By X-Ray Photoelectron Spectroscopy Analysis, Lauren B. Shepard May 2022

Analyzing The Surface Chemistry Of Ni-Fe Hydroxide Alloy Nanoparticles As Catalysts For The Oxygen Evolution Reaction By X-Ray Photoelectron Spectroscopy Analysis, Lauren B. Shepard

Chemical Engineering Undergraduate Honors Theses

Water electrolysis has been proposed as a renewable source of hydrogen, a possible replacement to harmful fossil fuels. This process can be broken down into two half reactions, the hydrogen evolution reaction and the oxygen evolution reaction. Because the oxygen evolution reaction has slow kinetics and a high overpotential to overcome, a catalyst is needed to speed up the kinetics and ensure faster and more efficient production of molecular hydrogen. The use of Ni-Fe hydroxide alloy nanoparticles as a catalyst has been shown to significantly improve the efficiency of the reaction by decreasing the overpotential, making the process more energy …


Electrode Development Of Water Electrolyzer Cells For Low-Cost And High-Efficiency Hydrogen Production, Shule Yu May 2022

Electrode Development Of Water Electrolyzer Cells For Low-Cost And High-Efficiency Hydrogen Production, Shule Yu

Doctoral Dissertations

A worldwide increase in energy demand and a latent crisis in the fossil fuel supply have spurred broad research in the renewable energy. Currently, most renewable energy resources (e.g., hydro, wind, solar, tide) face supply challenges as they are known to be intermittent, unstable, and locally shackled, which calls for urgent development in energy storage and conversion. Hydrogen is regarded as an ideal energy carrier with its advantages (e.g., high energy density, environmentally friendliness, and low weight). In practice, the proton exchange membrane electrolyzer cell (PEMEC) is considered to be one of the optimal hydrogen production and energy storage devices …


Optimizing Virus Prefiltration For Biopharmaceutical Manufacturing, Solomon Isu May 2022

Optimizing Virus Prefiltration For Biopharmaceutical Manufacturing, Solomon Isu

Graduate Theses and Dissertations

Virus filters are single-use devices that use a size-based separation process. In virus filters, contaminating virus particles are retained while the therapeutic molecules pass through the membrane pores. Virus filters are an essential component of the overall virus clearance strategy. Sections 1 and 2 of this dissertation provide an introduction and extensive review of monoclonal antibody (mAb) process development, where virus filtration is pivotal. In section 3, prefiltration studies were performed with an industrially relevant IgG1 type mAb using adsorptive and size-exclusion-based prefilters with different mechanisms of action. This mAb has an isoelectric point range of 7.1 to 8.0 and …


Catalytic Ring Opening Of Mono- And Bicyclic Compounds For The Production Of Renewable Diesel And Jet Fuel, Matthew J. Kline May 2022

Catalytic Ring Opening Of Mono- And Bicyclic Compounds For The Production Of Renewable Diesel And Jet Fuel, Matthew J. Kline

Electronic Theses and Dissertations

Thermal DeOxygenation (TDO) is a process that converts organic acids produced from cellulose hydrolysis and dehydration into a low-oxygen bio-oil containing substituted naphthene compounds. The high aromatic content is desirable for gasoline fractions, but middle distillates such as diesel and jet fuel require upgrading via hydrogenation and ring opening to achieve better combustion characteristics. Previous research has demonstrated that TDO oil could be hydrogenated over high-surface-area nickel catalysts to improve the combustion characteristics, but the cetane number was still below the specifications.

Multiple supported catalysts were synthesized by ion exchange and incipient wetness impregnation, and the catalysts were characterized by …


Structural, Charge Transport, Gas Sensing, Magnetic, Pseudocapacitive, And Electrocatalytic Properties Of Perovskite Oxides., Surendra Bahadur Karki May 2022

Structural, Charge Transport, Gas Sensing, Magnetic, Pseudocapacitive, And Electrocatalytic Properties Of Perovskite Oxides., Surendra Bahadur Karki

Electronic Theses and Dissertations

Perovskites are functional materials with the general formula ABO3 (A = alkali, alkaline earth or lanthanoid cations and B = transition metal or main group cations). These materials are marked by a variety of crystal structures and interesting properties such as colossal magnetoresistance, ferroelectricity, multiferroicity, superconductivity, pseudocapacitance, gas sensing, charge transport, and electrocatalytic properties. The formula of perovskite can be written as AA’BB’O6, when there is ordering between two cations over A and B-sites. Such compounds are called double perovskite oxides. Some amount of oxygen could be lost from crystal structure without decomposition of the phase. Such …


Computational Rational Design Of Electrocatalysts For Electrochemical Ammonia And Hydrogen Synthesis, Akash Jain Mar 2022

Computational Rational Design Of Electrocatalysts For Electrochemical Ammonia And Hydrogen Synthesis, Akash Jain

Doctoral Dissertations

The electrochemical hydrogen evolution reaction (HER) and nitrogen reduction reaction (NRR) offer fossil-fuel-free routes for hydrogen and ammonia synthesis, respectively. However, currently, both processes lack suitable electrocatalysts for practical applications. Thus, this dissertation focuses on the computational rational design of HER and NRR electrocatalysts.

HER is most efficiently catalyzed by platinum (Pt), which is expensive. To reduce the catalyst cost, we investigate core-shell nanoparticles of inexpensive tungsten-carbide (WC) and Pt (WC@Pt). Using first-principles density functional theory (DFT) calculations, we compare the suitability of two WC phases, α-WC and β-WC as support materials for Pt overlayers. We dope WC with titanium …


Computational Study Of The Reactions Of Heteroatomic Compounds On Ceo2, Suman Bhasker Ranganath Mar 2022

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 (Olatt) supplemented by phosphoryl O-Ce interaction is the only stable adsorption state for the un-dissociated molecule. Deprotonation of phosphate monoesters, …


Understanding The Photodegradation Mechanism Of Gaseous Acetaldehyde Over Bi2wo6 – Modified Znwo4 Photocatalyst Under Uv Light Irradiation, Mirabbos Hojamberdiev, Ronald Vargas, Shahlo Daminova, Zuhra Kadirova Feb 2022

Understanding The Photodegradation Mechanism Of Gaseous Acetaldehyde Over Bi2wo6 – Modified Znwo4 Photocatalyst Under Uv Light Irradiation, Mirabbos Hojamberdiev, Ronald Vargas, Shahlo Daminova, Zuhra Kadirova

CHEMISTRY AND CHEMICAL ENGINEERING

Indoor air quality has a significant impact on human health as people spend more time indoors. As a common indoor air pollutant, acetaldehyde is considered toxic when exposed to it for a prolonged period. The aim of this study is the enhancement of the photocatalytic activity of ZnWO4 with a monoclinic wolframite structure for degradation of gaseous acetaldehyde by modifying its surface with Bi2WO6 layered structure. The mechanisms behind the enhanced photocatalytic activity and the pathways for acetaldehyde photodegradation over the Bi2WO6-modified ZnWO4 photocatalyst are discussed.


Modelling Of Reаctive Distillаtion Process For Etherificаtion Reаction, Adham Norkobilov, Olimjon Mаksudov, Abdulaziz Bаkhtiyorov, Orifjon Zаripov, Abbos Elmаnov Feb 2022

Modelling Of Reаctive Distillаtion Process For Etherificаtion Reаction, Adham Norkobilov, Olimjon Mаksudov, Abdulaziz Bаkhtiyorov, Orifjon Zаripov, Abbos Elmаnov

CHEMISTRY AND CHEMICAL ENGINEERING

А reаctive distillаtion system is exаmined to produce for the production of Ethyl tert butyl ether (ETBE) viа etherificаtion of isobutene with ethаnol. Optimizаtion methods using heаt integrаtion аre аlso conducted. The molаr reflux rаtio аnd reboiler duty аre cаlculаted using sensitivity аnаlysis. The bottom streаm with the sаtisfied purity of ETBE is integrаted for heаting the feed streаm to the column. Heаt integrаtion from reаctor heаt to the initiаl feed streаm аnd from bottom streаm of the column to the column inlet streаm with the purpose of аchieving tаrget feed temperаture leаds to high conversion in the reаctive distillаtion …


Design And Fabrication Of Nanostructured Electrodes For Complementary Electrochemical And Photoelectrochemical Water Splitting, Kholoud El Sayed Abousalem Jan 2022

Design And Fabrication Of Nanostructured Electrodes For Complementary Electrochemical And Photoelectrochemical Water Splitting, Kholoud El Sayed Abousalem

Theses and Dissertations

Designing highly active, durable, and nonprecious electrodes for overall water splitting is of urgent scientific importance to realize sustainable hydrogen production. Accordingly, the need to search efficient energy production systems is of crucial necessity. In this thesis, two various systems for sustainable hydrogen production have been reported using electrochemical and photoelectrochemical pathways. In the first part of the thesis, electrochemical water splitting involving both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has been established. To this end, an innovative approach is demonstrated to synthesize flower-like 3D homogenous trimetallic Mn, Ni, Co phosphide catalysts directly on nickel foam via …


Controlling The Emission Of Volatile Platinum Oxides To The Vapor Phase In Diesel Oxidation Catalysts, Arnab Ghosh Jan 2022

Controlling The Emission Of Volatile Platinum Oxides To The Vapor Phase In Diesel Oxidation Catalysts, Arnab Ghosh

Nanoscience and Microsystems ETDs

Pt-based catalysts are used for the treatment of emissions from vehicles, particularly in Diesel oxidation catalysts (DOCs). Three-way catalysts are treated at temperatures ranging from 950℃-1050℃ while DOCs are aged at 800℃ for 50 hrs. At 800°C, Pt reacts with O2 to form PtO2 which has a high vapor pressure and can be transported through the vapor phase. These accelerated aging conditions lead to the formation of large Pt particles causing a loss of catalytic activity. In this thesis, we used model thin-film catalysts that made it possible to quantify the emission of Pt to the vapor phase …