Engineering Commons^™

Graphite And Graphene-Oxide Based Pgm-Free Model Catalysts For The Oxygen Reduction Reaction, Joseph Henry Dumont

Nanoscience and Microsystems ETDs

The world currently relies heavily on fossil fuels such as coal, oil, and natural gas for its energy. Fossil fuels are non-renewable, that is, they draw on finite resources that will eventually dwindle, becoming too expensive or too environmentally damaging to retrieve. One alternative source of energy are fuel cells, electrochemical devices that convert chemical energy to cleanly and efficiently produce electricity. They can be used in a wide range of applications, including transportation, stationary, portable and emergency power sources. Their development has been slowed by the high cost of PGM electrocatalysts needed at both electrodes as well as sluggish …

Nanoporous Solid Acid Materials For Biomass Conversion Into Value-Added Chemicals: Synthesis, Catalysis, And Chemistry, Hong Je Cho

Doctoral Dissertations

Growing environmental concerns associated with diminishing reserves of fossil fuels has led to accelerated research efforts towards the discovery of new catalytic processes for converting renewable lignocellulosic biomass into value-added chemicals. For this conversion, nanoporous solid acid materials have been widely used because of their excellent hydrothermal stability and molecular sieving capability. In the thesis, hierarchical Lewis acid zeolites with ordered mesoporosity and MFI topology (three dimensionally ordered mesoporous imprinted (3DOm-i) Sn-MFI) were successfully synthesized within the confined space of three dimensionally ordered mesoporous (3DOm) carbon by a seeded growth method. The obtained 3DOm-i Sn-MFI showed at least 3 times …

Energy From Chemical Reactions: Understanding The Combustion Engine, Tammy Guthrie, Kathy Prophet, Greg Herzig, Cassie Kautzer

Middle School Lesson Plans

Automobiles produce a large amount of heat generated by the burning of gasoline. Burning gasoline is a chemical reaction that causes a phase change. This is called combustible energy. During combustion fuel combines with oxygen to release energy (such as heat, light, sound) along with another product that is often considered waste. Most of the energy produced is not used to power the automobile, but is released as heat. 19.3 pounds of the greenhouse gas, carbon dioxide, is produced from the combustion of 1 gallon of U.S. gasoline according to the U.S. Energy Information Administration.

Electrochemical Synthesis Of Homoallylic Alcohols And Homoallylic Amines, Wei-Qiang Zhong, Xiang-Hui Liang, Jing-Mei Huang

Journal of Electrochemistry

Electrochemical technique has been widely applied in the organic synthesis. This review focuses on the electrochemical synthesis of homoallylic alcohols and homoallylic amines from the allylation of carbonyl compounds and imines. This method has been developed impressively, especially in the field of electrochemical allylation in a green solvent of aqueous media. Improvement of the efficiency of the electricity, regio-selectivity and chiral synthesis are expected.

Characteristics And Mechanism For The Simons Electrochemical Fluorination Of Methanesulfonyl Fluoride, Wen-Lin Xu, Bao-Tong Li, Da-Wei Wang, Ya-Qiong Wang

Journal of Electrochemistry

The characteristics and mechanism for the Simons electrochemical fluorination processes were investigated during the electrochemical fluorination of CH₃SO₂F to CF₃SO₂F. The results showed that the reaction mechanism for the electrochemical fluorination of organic compounds to organic fluorides was the same as that of chemical fluorination processes using fluorinating agents such as CoF₃. The electrochemical fluorination in anhydrous HF was a heterogeneous process, and nickel fluorides on the surface of the nickel anode played the role of a mediator in the Simons process to transfer oxidation potential from the anode to …

Ionic Liquid-Supported Tempo/Polymeric Ionic-Liquid/Carbon Black Ternary Composites: Preparations And Applications In Electrochemical Oxidation Of Alcohols, Xin Lin, Cao-Cao Sun, Zhi-Rong Liu, Cheng-Chu Zeng

Journal of Electrochemistry

To effectively recover redox catalyst and supporting electrolyte, a novel ternary composite consisting of ionic liquid-supported TEMPO, polymeric ionic-liquid and carbon black was prepared. The ionic-liquid supported redox catalyst TEMPO-IL-BF₄ was firstly synthesized from 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and followed by the reaction of polydimethyldiallylammonium chloride (PDDA) and bis(trifluoromethane)sulfonimide lithium salt (LiTFSI) to form poly[diallyldimethylammonium bis(trifluoromethanesulfonyl)imide] (PDDA(Tf₂N)). A combination of the above mentioned two synthesized materials and carbon black afforded to obtain the ternary composite, which was used as the recoverable supporting electrolyte and mediator for the electrochemical oxidation of alcohol. The results indicate that various alcohols could be oxidized …

Preparations And Applications Of Irsnox Electrode In Electrochemical Synthesis Of 2,5-Dichlorophenol, Xiang-Yu Ma, Xu-Guo Tu, Rui-Nan He, Ya Chen, Gui-Sheng Zhu, Shou-Yan Shao, Song Chen

Journal of Electrochemistry

The electrodes of titanium based iridium tin oxides (IrSnOx) have been prepared by traditional thermal decomposition method and further applied to the electrosynthsis of 2,5-dichlorophenol in order to explore a green and high efficient synthesis route. The results showed that the electrode surface existed apparent cracks, while the intermediate layer prepared with Sn:Sb=94:6 existed less cracks and longer life time. The main products of the electrolytic reaction were 2,5-dichlorophenol, p-chlorophenol, and 1,2,4-trichlorobenzene. The electrosynthsis yield of 2,5-dichlorophenol reached 57% and the selectivity of 2,5-dichlorophenol was as high as 93% by using the IrSnOx as an anode, which is obviously better …

Electrocatalysis Of Nanotin Dioxide In The Battery Reaction Of Zinc-Nitrobenzene, Xu-Guo Tu, Xiang-Yu Ma, Rui-Nan He, Xiao-Juan Wang, Chen Ling, Yun-Xia Sun, Song Chen

Journal of Electrochemistry

The tin dioxide (SnO₂) nanoparticles were synthesized by using a simple hydrothermal route in the presence of tetrapropyl ammonium bromide (TPAB) as a surfactant. Accordingly, the titanium mesh based SnO₂ catalyst electrode was prepared. The morphologies and structures of SnO₂ nanostructures were characterized by scanning electron microscopy and X-ray diffraction spectrometry. The influences of reactant concentration, reaction temperature and time on the morphology of the products were investigated in detail. The electrocatalytic performance of SnO₂ for the reduction of nitrobenzene with zinc was studied. Possible formation process and growth mechanism for such hierarchical SnO_{2 …}

Selective Direct Electro-Oxidation Of C-H Bond, Yan-Mei Liao, Qian-Qian Wu, An-Lun Zhang, Ying-Hong Zhu, Chun-An Ma

Journal of Electrochemistry

Carbon-hydrogen (C-H) bond is the most basic chemical bond in organic compounds. The activation and direct conversion of C-H bond are the effective methodology for synthesis of different kinds of organic compounds from alkane compounds. The oxidative activation and functionalization of C-H bonds constitute an important and challenging area of investigation. The electro-oxidative activation of C-H bonds to form new C-O, C-C and C-N bonds has proven to be interesting and important in organic chemistry using the clean electron as the oxidant. The target C-O, C-C and C-N compounds could be selectively achieved by choosing the appropriate electrode, supporting electrolyte …

Mo@ Pt Overlayers As Efficient Catalysts For Hydrodeoxygenation Of Guaiacol And Anisole, Qinghua Lai

Qinghua Lai

Acetone Production, Ali Ibrahim Neamah

The Hilltop Review

Iraq struggles with a lack of acetone production. This overall deficiency impacts the economy of countries like Iraq. Inasmuch, acetone is a vital chemical component for many items imported into this country such as nail polish remover. Therefore, a process of acetone production is proposed in this study.

The ideal process of producing acetone with 90.0% isopropyl alcohol (IPA) decomposition method is proposed within this study. The feed of the process is 100000 ton/ day. This amount of feed is suggested due to the demographic need of acetone for the Iraqi population as well as the surrounding Middle Eastern region. …

Methanol Steam Reforming: Na Doping Of Pt/Ysz Provides Fine Tuning Of Selectivity, Michela Martinelli, Gary Jacobs, Uschi M. Graham, Burtron H. Davis

Center for Applied Energy Research Faculty and Staff Publications

In this work, we found that sodium doping can be used to improve CO₂ selectivity for supported Pt catalyst during methanol steam reforming. These materials are usually very active in the low temperature range; however, they are characterized by high selectivity of CO, which is a poison in downstream polymer electrolyte membrane fuel cells (PEM-FC) application. With Na doping, we found that CO₂ selectivity was higher than 90% when 2.5 wt.% of sodium was added to Pt/YSZ. We have speculated that the different product distribution is due to a different reaction pathway being opened for CH₃OH …

Catalytic Hydrodeoxygenation And Dehydration Of Bioderived Oxygenates To Renewable Hydrocarbon Building Block Molecules: Enabling Renewable Carbon Fiber, Andrew Walter Lepore

Doctoral Dissertations

It is our goal to develop inexpensive catalytic pathways that can effectively remove oxygen from bio-derived carboxylic acids and alcohols under mild reaction conditions to produce propene which can be converted to renewable carbon fibers. Carboxylic acid hydrodeoxygenation and alcohol dehydration are necessary for successfully producing propene from bio-mass derived precursors and are also broadly relevant to bio-oil upgrading. This body of research adds to the understanding of both known and novel catalyst materials and develops and optimizes pathways for valorizing oxygenates. Dehydration and hydrodeoxygenation catalysts were examined under both batch and continuous flow operation. Product selectivity and reactant conversion …

Sec-Butanol From Crude Butene Feedstock Plant Design, Samantha How, Jacob Przywara, Bryce Robbins, Gavino Valdez

Senior Theses

Sec-butanol, C4H10O, is a flammable alcohol that is widely used as a fuel additive or as a reactant to make butanone, an industrial solvent. A hydration reaction between n-butenes and water, catalyzed by sulfuric acid, is a commonly used process in producing sec-butanol. However, a more challenging reaction and separation scheme is presented with a crude feedstock of butenes because of the abundance of azeotropes produced by side reactions. The development of a new plant design is relevant to industrial chemical plants that produce large amounts of crude butene side products, and can be useful by increasing plant efficiency and …

Designing Pt-Skin Of Pt-Based Bimetallic Electrocatalysts For Oxygen Reduction Reaction, Binwei Zhang, Yunxiao Wang, Yanfei Xu, Huakun Liu, Shixue Dou

Journal of Electrochemistry

In the past decade, great advancement has been made in the development of nanocatalysts for energy conversion and storage. Pt-skin of Pt-based bimetallic has shown a great potential in the tuning the electronic structures of electrocatalytically active materials toward oxygen reduction reaction. Here, we offer a brief overview of the recent research on the design and preparation of catalysts. Our focus is paid on the systematic studies of preparation and performance of Pt-skin catalysts towards oxygen reduction reaction.

Recent Progress In Template-Assisted Synthesis Of Nitrogen-Doped Porous Carbons For Oxygen Electroreduction, Niu Wenhan, Li Ligui, Shaowei Chen And

Journal of Electrochemistry

Nitrogen (N)-doped porous carbons are potential alternatives to precious metal catalysts for oxygen reduction reaction (ORR) at the cathodes of proton exchange membrane fuel cells and metal-air batteries. Template-assisted synthesis has been used extensively as a robust and versatile method in the preparation of such carbon catalysts, where the ORR activity has been found to be dependent on various structural parameters, such as the concentrations and molecular configurations of the dopants, and the porosity, surface accessibility and electrical conductivity of the carbon materials. In this review, we summarize recent progress in this area of research focusing on the design, preparation …

Comparative Studies Of Fe, Ni, Co And Their Bimetallic Nanoparticles For Electrochemical Water Oxidation, Maduraiveeran Govindhan, Brennan Mao, Aicheng Chen

Journal of Electrochemistry

The design of efficient, durable, and earth-abundant electrocatalysts via environmentally compatible strategies for the oxygen evolution reaction (OER) is a vital for energy conversion processes. Herein we report a facile approach for the fabrication of low-cost and earth abundant metal catalysts, including iron (Fe), nickel (Ni), cobalt (Co), CoNi, and CoFe nanoparticles (NPs) on titanium (Ti) substrates through a one-step electrochemical deposition. Field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) spectrocopy, X-ray photoelectron spectroscopy (XPS), and electrochemical techniques were employed to characterize these nanoparticles. Our electrochemical results revealed that among the five synthesized nanomaterials, the …

Impact Of Nafion Loading And Anion Adsorption On The Synthesis Of Pt Monolayer Core-Shell Catalysts, Lijun Yang, Dustin Banham, Elod Gyenge, Siyu Ye

Journal of Electrochemistry

Carbon supported palladium (Pd) nanoparticles were used as a model core material for the synthesis of platinum (Pt) monolayer core-shell catalysts using rotating disk electrode method and a copper (Cu) under potential deposition technique. The impact of Nafion on the synthesis process was revealed by electrochemical testing with various Nafion contents. The existence of Nafion influenced the Cu under potential deposition, galvanic replacement and eventually the oxygen reduction reaction activity of the core-shell catalyst. However, as long as the Nafion content was less than 5 wt% in the test film, adding Nafion could help to bind catalyst onto the surface …

Comparison Of Oxygen Reduction Reaction Activity Of Pt-Alloy Nanocubes, Yongan Tang, Lin Dai, Shouzhong Zou

Journal of Electrochemistry

Alloying Pt with the first row non-noble transition metals has been demonstrated to increase the catalytic activity toward oxygen reduction reaction (ORR), which is the cathode reaction of the proton exchange membrane fuel cells (PEMFCs) and metal-air batteries. However, how much the ORR activity improvement comes from the alloying elements remains controversial. In this paper, the nanocubes of PtMn, PtFe, PtCo, and PtNi with the similar size and composition were prepared and their ORR activities were explored, in order to investigate the effects of alloying elements on the catalytic activity. The use of cubic shape particles minimizes the contribution to …

Electrodeposition Of Ruo2 Layers On Tio2 Nanotube Array Toward Co2 Electroreduction, Bei Jiang, Lina Zhang, Xianxian Qin, Wenbin Cai

Journal of Electrochemistry

RuO₂/TiO₂ composite materials have multitude of electrocatalytic applications including but not limited to CO₂ reduction reaction (CO₂RR). RuO₂/TiO₂ electrodes were previously prepared by repetitive coating and thermal decomposition (TD) of a Ru(III) precursor solution on Ti substrate. In this work, electrochemical potential cycling is applied to deposit amorphous RuO₂ (α-RuO₂) layers onto TiO₂ nanotube array (TNA) (RuO₂^CV/TNA) preformed on Ti foil. SEM, GIXRD, and voltammetry are applied to characterize the structures of the resulting Ru_O2^CV/TNA. Ru loading on the RuO_{2 …}

Design Of 3d Macroporous Inverse Opal Tio2 Binary And Ternary Composites Sensitized With Gold Nanoparticles And Cds Quantum Dots For Photocatalysis, Daniel A. Corella

Master of Science in Chemical Sciences Theses

Materials composed of titanium (IV) oxide (TiO₂) have received enormous scientific interest due to titania’s abundance, non-toxicity, and photocatalytic proficiency, however its large band gap limits its applicability under ambient conditions. Various attempts have been made to incorporate titania into composite systems to sensitize it for activity under a broader range of wavelengths. One such method includes utilizing narrow band gap semiconductors to form an electron transfer process analogous to photosynthesis referred to as a Z-scheme. Z-scheme systems can catalyze the decomposition of aqueous pollutants via generation of reactive oxygen species after input of sunlight. This work reports …

Photoactive Properties Of Nanostructured Titania Modified Polyurethanes, Chao Chen

Electronic Thesis and Dissertation Repository

In order to enhance both the photoactivity and physical/mechanical properties of titania/polyurethane (PU) nanocomposites, in-situ polymerization and film casting were investigated. Both self-degrading PU foams and self-cleaning PU coatings were prepared. Functional monomers were prepared usingDMPA (2,2-dimethylolpropionic acid) functionalized anatse TiO₂ and P25 for integration into polyurethane foam with a "grafting-from" synthetic method. This technique was found to successfully reduce the agglomeration effect of titania nanoparticles inside the foams. In addition, the photodegradation rate was enhanced by > 120% over unmodified foam at an optimized loading of 3wt% DMPA functionalized anatase TiO₂. The presence of DMPA functionalized P25 …

Investigation Of Copper Catalysts For Propylene Epoxidation, Hayden Fowler, Zheng Lu

Research Horizons Day Posters

No abstract provided.

Activity Of Pgm-Free Electrocatalysts For Oxygen Reduction Reaction: Ph And Co-Catalysis Effects, Mario Santiago Rojas Carbonell 8148369

Chemical and Biological Engineering ETDs

Fuel cells offer a source to the current and always increasing demand for electric power. But as any new technology, there are challenges that need to be addressed to render it feasible for the market place. One of this challenges is finding the appropriate materials to catalyze the oxygen reduction reaction (ORR) that occurs in the cathode. Oxygen is used as an oxidant in a significant portion of the fuel cells due to its readily availability and high reduction potential. Now, one the bottlenecks that stops the large-scale adoption is the expensive and rare metals that have been used as …

Multi-Objective Optimization Of Industrial Ammonia Synthesis, Stanislav Ivanov

Electronic Thesis and Dissertation Repository

The thesis describes modelling and optimization work of an industrial ammonia synthesis. Author developed first-principle mathematical model of the commercial converter based on gas-solid reaction and heat transfer within the system. The model is validated with industrial data and showed satisfactory accuracy. Further, optimization study is performed in multi-objective manner to intensify ammonia production and decrease heat duty of the process. Result have revealed a potential to improve current operating condition int terms of both objectives.

Supercritical Fluid Extraction Of Valuable Chemicals: Application Of Microalgae And Pyrolysis Oil As Feedstocks, Osariemen Ogbeide

Electronic Thesis and Dissertation Repository

In this dissertation, pure and modified carbon dioxide were used as non-conventional solvents for the investigation of lutein, chlorophyll a, chlorophyll b extraction from microalgae and for caffeine extraction from the pyrolysis oil of spent coffee grounds. The use of toxic organic solvents in supercritical fluid extraction has propelled research efforts to develop new solvents that are environmentally friendly and provide faster extraction compared to conventional extraction processes. For this reason, phosphatidylethanolamine (PE), a major phospholipid consisting of 14% of the entire soybean lecithin was acetylated with acetic anhydride, providing a surfactant (N-A-PE).

Then, the synthesized N-A-PE was employed as …

Synthesis, Characterization, And Properties Of Graphene-Based Hybrids With Cobalt Oxides For Electrochemical Energy Storage And Electrocatalytic Glucose Sensing, Sara C. Botero Carrizosa

Masters Theses & Specialist Projects

A library of graphene-based hybrid materials was synthesized as novel hybrid electrochemical electrodes for electrochemical energy conversion and storage devices and electrocatalytical sensing namely enzymeless glucose sensing. The materials used were supercapacitive graphene-family nanomaterials (multilayer graphene-MLG; graphene oxide-GO, chemically reduced GO-rGO and electrochemical reduced GOErGO) and pseudocapacitive nanostructured transition metal oxides including cobalt oxide polymorphs (CoO and Co3O4) and cobalt nanoparticles (CoNP). These were combined through physisorption, electrodeposition, and hydrothermal syntheses approaches. This project was carried out to enhance electrochemical performance and to develop electrocatalytic platforms by tailoring structural properties and desired interfaces. Particularly, electrodeposition and hydrothermal synthesis facilitate chemically-bridged …

A Study Of Iron-Nitrogen-Carbon Fuel Cell Catalysts: Chemistry – Nanostructure – Performance, Michael J. Workman

Nanoscience and Microsystems ETDs

Fuel cells have the potential to be a pollution-free, low-cost, and energy efficient alternative to the internal combustion engine for transportation and small-scale stationary power applications. The current state of fuel cell technology has already achieved two of these three lofty goals. The remaining barrier to wide-scale deployment is the high cost, which is primarily caused by dependence on large amounts of platinum to catalyze the energy conversion reactions. To overcome this barrier and facilitate the integration of fuel cells into mainstream applications, research into a new class of catalyst materials that do not require platinum is needed.

There has …

Characterization Of Iron Phthalocyanine As The Cathode Active Material For Lithium-Ion Batteries, Sarwan S. Sandhu, Joseph P. Fellner

Sarwan S. Sandhu

The developed thermodynamic functions for the determination of Gibbs free energy, enthalpy, and entropy of formation of solid lithium-iron phthalocyanine (LixFePc) from solid lithium and iron phthalocyanine as a function of x, defined as g-moles of the intercalated lithium per g-mole of iron phthalocyanine, at a fixed set of temperature and pressure conditions are presented. In addition, a proposed expression for the evaluation of lithium diffusion coefficient in solid iron phthalocyanine as a function of both x and temperature, and the experimental results from the ongoing research/development work on the lithium/iron phthalocyanine cells are included.

Application Of Composite Ionic Liquid In Electro-Oxidation Activation Of A C-H Bond, Zi-Ying Chen, Qian-Qian Wu, Jian-Qing Zhang, Ying-Hong Zhu, Chun-An Ma

Journal of Electrochemistry

In this paper, the ionic liquid/carbon nanotube composite material was prepared through modifying the ionic liquid 1-ethyl-3-methylimidazolium acetate to multi-walled carbon nanotubes. The electro-oxidation properties of p-methoxy toluene (p-MT) were studied using the composite as an electrolyte. The effects of scanning speed, temperature and substrate concentration were studied by cyclic voltammetry and chronoamperometry. The electrochemical kinetics of p-MT in this system was also studied. The results showed that the electrochemical oxidation of p-MT in the composite electrolyte solution was irreversible. The process was mainly controlled by diffusion, and the diffusion coefficient (D) was 7.69×10-10 cm2.s-1. Increasing the reaction temperature and …