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Carbon dioxide

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Towards Carbon Dioxide Reduction: Synthesis And Characterization Of Ccc-Nhc Pincer Iron Complexes., Joshua Mensah May 2024

Towards Carbon Dioxide Reduction: Synthesis And Characterization Of Ccc-Nhc Pincer Iron Complexes., Joshua Mensah

Theses and Dissertations

The industrial revolution came with its downside of emission of greenhouse gases into the atmosphere. The NOAA reported in 2019 that, of the greenhouse gases emitted into the atmosphere, CO2 contributed to about 80% of the increased greenhouse gases hence the need for CO2 Sequestering and Storage (CSS) and ultimately leading to Carbon Capture and Recycling (CCR) as a viable option to convert CO2 into useful forms. The race to find the best catalyst for CCR has led to the synthesis of many organometallic compounds. Pincer complexes catalyzed CO2 reduction has gained notoriety recently because of the tunability and robustness …


The Effect Of Solvent Identity And Hydride-Donor On The Reduction Of Co2 Into Useful Fuels, Abigail Mcentire Jan 2024

The Effect Of Solvent Identity And Hydride-Donor On The Reduction Of Co2 Into Useful Fuels, Abigail Mcentire

Honors Theses

One possible strategy for decreasing CO2 emissions is through electrocatalytic reduction reactions to convert the CO2 back into combustible fuels , such as methane or methanol. However, it can be challenging to control the reaction to select one of these useful fuels as opposed to carbon monoxide or formate. Our strategy is to investigate a specific hydride donor and solvent combinations for which the reaction favors conversion to methanol. It was found that in acetonitrile , several hydride donors were capable of selective reduction of CO2 to the methanol oxidation state.


Modeling Surface Structures For The Capture Of Carbon Dioxide, Paige Freyre May 2023

Modeling Surface Structures For The Capture Of Carbon Dioxide, Paige Freyre

Honors Theses

Our research utilized a modified graphene surface model to simulate capture of carbon dioxide and nitrogen gas based on van der Waals forces and hydrogen bonding. We completed an extensive review of the literature for model and experimental surfaces used to trap carbon dioxide and nitrogen gas into structures and pores with varying functional groups, pore sizes, and pore structures. We replicated the design of selected published models and compared their and our calculated binding energies. We used Scigress (Fujitsu) software with the Molecular Mechanics MM3 parameter set to perform calculations to analyze a proposed graphene surface pore lined with …


Food Waste Storage Gaseous Emissions Detection And Quantification Using Infrared Spectroscopy, Ryley A. Burton-Tauzer Jan 2023

Food Waste Storage Gaseous Emissions Detection And Quantification Using Infrared Spectroscopy, Ryley A. Burton-Tauzer

Cal Poly Humboldt theses and projects

A growing interest in sustainable waste management and the implementation of new policies have prompted a shift towards alternative resource recovery methods for organic waste, including food waste. To effectively assess alternative food waste treatment scenarios, it is important to evaluate the life cycle impacts associated with each scenario. The storage phase of food waste, encompassing its accumulation in kitchens, and storage in bins for collection and transportation, has been overlooked as a source of greenhouse gases in previous studies. This investigation aimed to identify the greenhouse gases emitted during the initial five-day period of low-oxygen storage. An open dynamic …


Heterogenous Reduction Of Co2 Over Boron-Rich Alb2, Jose C. Berger Jan 2022

Heterogenous Reduction Of Co2 Over Boron-Rich Alb2, Jose C. Berger

Honors Undergraduate Theses

Evidence suggests that the recent drastic changes in the global climate have been caused by greenhouse gases, especially CO­2. As a result, scientists are aiming to develop processes that either minimize the production of these gases or convert them into products of higher value. To that end, the catalytic properties of a two-dimensional boron-rich material were investigated. Herein is reported that such a material can reduce CO2 into benzene, C3 species, and C4 species at relatively low temperatures (225-450 ℃) and pressures (0.38 MPa). Current data suggest that a low-temperature induction period (e.g., 225 ℃) …


The Variability Of Seawater Carbonate Chemistry In Two Florida Urban Mangrove Ecosystems, Alexandrina R. Rangel Aug 2021

The Variability Of Seawater Carbonate Chemistry In Two Florida Urban Mangrove Ecosystems, Alexandrina R. Rangel

All HCAS Student Capstones, Theses, and Dissertations

Anthropogenic carbon dioxide (CO2) emissions into the atmosphere are yielding serious impacts across the world’s ocean, including ocean acidification, sea level rise, and increasing seawater temperature. However, these changes are not occurring uniformly across all marine ecosystems. Coastal ecosystems, such as mangroves, already experience extreme and variable environmental conditions due to natural biogeochemical and physical processes. The goal of this study was to document small-scale variability in two urban mangrove ecosystems to gain insight into how ocean acidification will manifest within these systems. Using a stand-up paddleboard, a suite of sensors, and traditional bottle sampling techniques, we measured …


Interactions Of Carbon Dioxide On Nickel Surface: A Reactive Molecular Dynamics Study Of Plasma- Catalysis, Leticia Adao Gomes Jan 2021

Interactions Of Carbon Dioxide On Nickel Surface: A Reactive Molecular Dynamics Study Of Plasma- Catalysis, Leticia Adao Gomes

Undergraduate Theses and Capstone Projects

The adsorption probability and reaction behavior of CO2 on nickel catalyst surfaces are investigated employing reactive molecular dynamics (MD) simulations using the ReaxFF potential. Such catalyst is used in the dry reforming reaction where greenhouse gases, carbon dioxide and methane, react producing synthesis gas, a potential clean energy source. However, this reaction is strongly endothermic due to the reactants' thermodynamic stability and requires a significant amount of energy. The selectivity and energy efficiency can be improved by combining a nonthermal plasma with a catalyst. Further insight into the underlying mechanisms of this process is needed to increase its applicability. Through …


Simple Photochemical Reduction Of Carbon Dioxide To Formate, Ovuokenye Omadoko Aug 2019

Simple Photochemical Reduction Of Carbon Dioxide To Formate, Ovuokenye Omadoko

Electronic Theses and Dissertations

There is a need to develop techniques for conversion of carbon dioxide to other useful products such as methanol, formaldehyde, formic acid, formate, methane, and hydrocarbons. Carbon dioxide can be converted into these products using different methods such as photochemical, electrochemical, thermochemical and hydrogenation by bacteria. Formate is of interest due to its wide industrial applications which include it’s use in direct liquid fuel cells, as an additive in pyrolysis vapors, a precursor for biological fuels, and it is a key intermediate in methanogenesis breaking down complex organic compounds. In this work, conversion of carbon dioxide to formate was accomplished …


Electrodeposition Of Hydrogen Molybdenum Bronze Films And Electrochemical Reduction Of Carbon Dioxide At Low Over Potentials, Sami Alharbi Aug 2019

Electrodeposition Of Hydrogen Molybdenum Bronze Films And Electrochemical Reduction Of Carbon Dioxide At Low Over Potentials, Sami Alharbi

Electronic Theses and Dissertations

Hydrogen molybdenum oxide, known has molybdenum bronze, is a material of interest due to catalyzing electron transfer reactions. Specifically, molybdenum bronze is an electrocatalyst toward carbon dioxide reduction. Electrochemical deposition from a peroxymolybdic acid solution is a method for preparing molybdenum bronze films. This work demonstrates reproducible electrodeposition on indium tin oxide substrates and conductive carbon paper. Film thickness depends on concentration, time and pH. After characterization by film thickness, resistance, XRD and XPS, the as deposited films served as the working electrode for electrochemical reduction of carbon dioxide in 0.1 M NaHCO3. Ion chromatography determined formate resulting …


Studying Carbon Dioxide Solvent Properties By Microwave Spectroscopic Investigations Of Vinyl Fluoride/Carbon Dioxide Clusters And Developing New Approaches To Decode Rotational Spectra, Prashansa Kannangara Jan 2019

Studying Carbon Dioxide Solvent Properties By Microwave Spectroscopic Investigations Of Vinyl Fluoride/Carbon Dioxide Clusters And Developing New Approaches To Decode Rotational Spectra, Prashansa Kannangara

Masters Theses

Supercritical carbon dioxide (sc-C02) is an excellent green solvent, but its properties are not thoroughly understood. For example, fluorinated compounds have higher than expected solubility in sc-C02. Microwave spectroscopy is one way to learn more about sc-C02 because it can be used to determine detailed structures of small clusters of molecules. The purpose of this investigation was to study weak hydrogen bonding interactions in complexes of fluorinated ethylene (solute) with carbon dioxide (C02, solvent). Investigations on dimers with one C02 molecule and fluorinated ethylene were carried out previously and found two different …


Increased Utility Of Ph Sensitive Indicators As High Concentration Co2 Detectors Through The Use Of Polyelectrolyte Complexes As Stabilizing Media, Camden James Johnson Jan 2019

Increased Utility Of Ph Sensitive Indicators As High Concentration Co2 Detectors Through The Use Of Polyelectrolyte Complexes As Stabilizing Media, Camden James Johnson

All Master's Theses

Development of plastic materials which produce visible color change when exposed to different environments has recently attracted attention for many biomedical applications.1,2Many biomedical devices are packaged under high concentrations of carbon dioxide (CO2) which can lower the pH of the packaging environment. This is similar to the CO2 chemistry responsible for ocean acidification.3 Dye molecules that are sensitive to environmental changes in pH (known as pH indicators) can be encapsulated in plastics and produce a visible color change when a medical device is removed from the sterile CO2 environment. Plastics made from large …


Novel Relative Spontaneous Ignition Temperature Determination Using Carbon Dioxide Onset With Sta/Ir, Antonio David Trevino Aug 2018

Novel Relative Spontaneous Ignition Temperature Determination Using Carbon Dioxide Onset With Sta/Ir, Antonio David Trevino

Electronic Theses and Dissertations

Simultaneous thermal analysis, coupled with infrared spectroscopy (STA/IR), was utilized to monitor the evolution of gaseous products during the thermal degradation of samples from Triadica sebifera (Chinese tallow), Ligustrum sinense (Chinese privet), and Ilex vomitoria (yaupon) plants. Identification of carbon dioxide was successful with a spectral match of 90.2 percent and further used in the determination of relative spontaneous ignition temperature, or RSIT. The RSIT value during the growing season for Chinese tallow, Chinese tallow stem, Chinese privet, and Yaupon were 208.4°C, 250.3°C, 210.1°C, and 232.3°C respectively. During the dormant seasons, the values for Chinese tallow stem, Chinese privet, and …


Nanoporous Carbon-Based Co2 Reduction Catalysts: Exploring The Combined Effects Of Surface Chemistry And Porosity, Wanlu Li Feb 2018

Nanoporous Carbon-Based Co2 Reduction Catalysts: Exploring The Combined Effects Of Surface Chemistry And Porosity, Wanlu Li

Dissertations, Theses, and Capstone Projects

For the first-time sulfur-doped, nitrogen-doped and sulfur, nitrogen-codoped nanoporous carbons were systematically studied as catalysts for CO2 electrochemical reduction reaction (CO2ERR). The Faradaic efficiencies (FE) of CO and CH4 formation were calculated to evaluate the performance of these carbons. The best catalysts showed the FE of CO and CH4 formation of 29% and 0.76%, respectively. It was found that the overall performance in CO2ERR dramatically increased upon the reduction pretreatment of the carbons in N2-saturated electrolyte before the CO2 reduction process. The pretreated carbon showed the maximum FE of CO …


Water Chemistry Dynamics In Four Vernal Pools In Maine, Usa, Lydia H. Kifner Dec 2017

Water Chemistry Dynamics In Four Vernal Pools In Maine, Usa, Lydia H. Kifner

Electronic Theses and Dissertations

Vernal pools are small seasonal wetlands that are a common landscape feature that contribute to biodiversity in northeastern North American forests. However, even basic information about their biogeochemical functions, such as carbon cycling, is limited. Dissolved gas concentrations (CH4, CO2) and other water chemistry parameters were monitored weekly at the bottom and surface of four vernal pools in central and eastern Maine, USA, from April to August 2016. The vernal pools were supersaturated with respect to CH4 and CO2 at all sampling dates and locations. Concentrations of dissolved CH4 and CO2 ranged …


Doped Tio2 Nanowires For Applications In Dye Sensitized Solar Cells And Sacrifical Hydrogen Production, Qasem Alsharari Apr 2016

Doped Tio2 Nanowires For Applications In Dye Sensitized Solar Cells And Sacrifical Hydrogen Production, Qasem Alsharari

Electronic Thesis and Dissertation Repository

This thesis explores the synthesis of metal oxide 1-D nanowires using a sol-gel method in supercritical carbon dioxide (sc-CO2), as an environmental friendly enabling solvent. Porous nanowires were synthesized and their performance was tested in dye sensitized solar cell and sacrifical hydrogen production. Titanium isopropoxide (TIP) was used as a precursor for titania synthesis while copper, bismuth and indium were examined as dopants, respectively. The sol-gel reactions were catalyzed by acetic acid in CO2 at a temperature of 60 °C and pressure of 5000 psi. It was observed that acetic acid/monomer ratio > 4 produced nanowires while a …


Siloxane And Silane-Functionalized Polynorbornenes As Membranes For Passive Carbon Dioxide Separation, Eunice Koheun Hong Dec 2015

Siloxane And Silane-Functionalized Polynorbornenes As Membranes For Passive Carbon Dioxide Separation, Eunice Koheun Hong

Masters Theses

In 2012, carbon dioxide (CO2) [carbon dioxide] accounted for approximately 82% [percent] of all U.S greenhouse gas emissions.1 These excessive CO2 levels have been attributed to climate changes that have a range of negative effects on human health and welfare.1 In an effort to decrease these emissions, polymeric membranes consisting of silane- and siloxane-functionalized norbornene units have been targeted as a potential solution for the passive separation of CO2 from other non-greenhouse gases. These substituted norbornene-based polymers were synthesized via vinyl-addition polymerization. Through a series of catalyst trials, commercially available palladium and nickel catalysts were compared along …


Development And Evaluation Of Carbon-Based Quantum Dots For Carbon Dioxide Photoconversion, Sushant Sahu Sep 2014

Development And Evaluation Of Carbon-Based Quantum Dots For Carbon Dioxide Photoconversion, Sushant Sahu

All Dissertations

World energy consumption has increasingly grown over the past several decades.Because of its potential in photochemical energy conversion, photocatalysis has been the subject of much recent research. Recently, carbon or graphene-based quantum dots have attracted growing attention in solar energy conversion applications, because of its unique optoelectronic properties, broad-band optical absorption, bright fluorescence emissions, favorable photoinduced electron transfer properties, reliable chemical inertness and stability, cost-effectiveness, and non-toxicity. While nanosized wide band gap semiconductor-based systems were largely at the center of attention in such studies, carbon-based quantum dots have recently emerged as a new class of semiconductor like photoactive materials, due …


Carbon Sequestration In Tidal Salt Marshes And Mangrove Ecosystems, Carlos Eduardo Quintana-Alcantara May 2014

Carbon Sequestration In Tidal Salt Marshes And Mangrove Ecosystems, Carlos Eduardo Quintana-Alcantara

Master's Projects and Capstones

Wetlands are dynamic systems that provide support to vital environmental functions and services. Wetlands take part in the global carbon cycle by holding organic carbon in biomass, soils and sediments. In recent years, the wetland carbon sequestration capacity has been researched worldwide due to the increase of the concentrations of greenhouse gasses implicated in global warming and climate change. Although coastal wetlands release the greenhouse gasses carbon dioxide, methane and nitrous oxide, these ecosystems maintain high performance in offsetting significant amounts of atmospheric carbon. This paper investigated the carbon sequestration capacity of coastal wetland ecosystems summarizing the environmental conditions and …


The Spectrophotometric Analysis Of Lead Carbonate Complexation And Carbonate Saturation States In Seawater, Regina Anita Easley Jan 2013

The Spectrophotometric Analysis Of Lead Carbonate Complexation And Carbonate Saturation States In Seawater, Regina Anita Easley

USF Tampa Graduate Theses and Dissertations

The carbon dioxide (CO2) system is the primary buffer in seawater which controls oceanic pH. Changes in the marine CO2 system affect a number of processes such as metal speciation, mineral saturation states, auditory responses in fish, and primary productivity rates. Increased atmospheric concentrations of CO2 from human activities (e.g. burning of fossil fuels, deforestation, and cement production) has led to a global decrease in surface ocean pH termed anthropogenic ocean acidification. One particular concern in response to increased oceanic CO2 is a substantial decrease in the calcium carbonate (CaCO3) saturation states, Ω …


Mesoporous Functionalized Materials For Post-Combustion Carbon Dioxide Capture., Kolade Omoniyi Ojo Dec 2011

Mesoporous Functionalized Materials For Post-Combustion Carbon Dioxide Capture., Kolade Omoniyi Ojo

Electronic Theses and Dissertations

Novel highly functionalized hybrid organic-inorganic materials were synthesized by polycondensation of bis[3-(trimethoxysilyl)propyl]amine in presence of cationic and anionic surfactants. Reaction media strongly affected gelation time. Thus, in basic media gelation occurred immediately while acid increased gelation time. Material structures were studied by IR spectroscopy, porosimetry, XRD, and SAXS methods. In spite of the absence of an inorganic linker, obtained bridged silsesquioxanes had mesoporous structure. A material prepared in the presence of dodecylamine as a template had higher surface area and narrow pore size distribution while the use of sodium dodecylbenzene sulfate resulted in formation of mesopores with wide size ranges. …


Super Collision Energy Transfer Studies In Single Collisions Between Vibrationally Hot Benzene Like Molecules And Ground State Bath Molecules: The Effect Of Physical Properties Of Donor And Bath Molecules On Super Collision Energy Transfer, Kilyoung Kim Mar 2011

Super Collision Energy Transfer Studies In Single Collisions Between Vibrationally Hot Benzene Like Molecules And Ground State Bath Molecules: The Effect Of Physical Properties Of Donor And Bath Molecules On Super Collision Energy Transfer, Kilyoung Kim

Theses and Dissertations

This research is focused on single-collision energy transfer events between highly vibrationally excited benzene-like donor molecules and small bath molecules, CO2 and N2O in the vibrational ground level. Measuring how much energy is transferred from donors to bath molecules was accomplished by probing bath molecules scattered into specific-rotational states using a tunable Δv=0.0003 cm-1 solid state diode laser. The normalized energy transfer probability distribution function, P(E,E'), determined from energy gain information, is very useful in comparing collisional energy transfer efficiency between various collision systems. P(E,E') is also used to investigate the effects of donor and bath physical properties on collisional …


Liquid Carbon Dioxide Extraction Of Various Food Flavors: Evaluation And Analysis, Deven Lee Shinholt Apr 2009

Liquid Carbon Dioxide Extraction Of Various Food Flavors: Evaluation And Analysis, Deven Lee Shinholt

Undergraduate Honors Thesis Collection

Sub- and supercritical carbon dioxide has been utilized as an extraction solvent for a variety of natural compounds. This requires the use of specialized high-pressure vessels. It was reported recently that common laboratory apparatus (centrifuge tubes) could be utilized in liquid carbon dioxide extractions obviating the need for specialized equipment. Various herbs and spices (including orange, lemon, lime, and grapefruit zest, oregano, rosemary, sage, spearmint, nutmeg, black peppercorns, cloves, caraway seeds, and vanilla beans) were used as substrates for liquid carbon dioxide extractions by this straightforward technique. The extracted oils, containing terpenes and terpenoids, were then analyzed through GC/MS. Liquid …


An Analysis Of The Effect Of Carbon Dioxide On The Decay Rates Of Superoxide, Michael Jay Walsh Jan 2005

An Analysis Of The Effect Of Carbon Dioxide On The Decay Rates Of Superoxide, Michael Jay Walsh

Honors Theses

The radical dioxygen anion, superoxide has been shown to react with carbon dioxide in nonprotic and aqueous systems. Indirect evidence suggests that superoxide also reacts with carbon dioxide and carbonate species dissolved in water. This study involved conducting experiments to determine the decay rate of superoxide in the presence of carbon dioxide and carbonate species. Experiments were conducted by sparging an alkaline bicarbonate buffer with carbon dioxide and measuring the decay rate of superoxide added to the solution. Although the specific reaction mechanism and rates have not been determined first order superoxide decay rates as high as 3.8x10-2s-1 were obtained …


Study Of The Effects Of Co2(G) On The Fe(Ii)-Luminol Chemiluminescence System: Application To Ultra-Trace Analysis Of Fe(Ii), Sara Beth Lovitz Jan 2001

Study Of The Effects Of Co2(G) On The Fe(Ii)-Luminol Chemiluminescence System: Application To Ultra-Trace Analysis Of Fe(Ii), Sara Beth Lovitz

Honors Theses

The Fe(II)-catalyzed oxidation of luminol has been a well-accepted chemiluminescence method for the trace and ultra-trace analysis of Fe(II) and Fe(III) in natural waters. Investigation into this chemiluminescence system has shown that COlg) is essential to Fe-catalyzed luminol chemiluminescence. In absence of CO2(g) there is no chemiluminescent signal. These reactions worked well in the past because CO2 is present in most laboratory H20 supplies. Intentional saturation of CO2 results in a 5-fold increase for this conventional system. We propose a mechanism for CO 2(g) enhancement that includes formation of a CO2-superoxide intermediate, which serves as the oxidant of luminol to …


Kinetics Of The Reaction Of Isatoic Anhydride With Low Molecular Weight Alcohols, William Mast May 1962

Kinetics Of The Reaction Of Isatoic Anhydride With Low Molecular Weight Alcohols, William Mast

Chemistry Honors Papers

This 22 page thesis studies the kinetics of the reaction of isatoic anhydride with low-molecular-weight alcohols by a colorimetric method.


Gas - Volumetric Semimicrodetermination Of Carbon: A Wet Method For Aliphatic And Cyclic Compounds, Roger P. Staiger May 1943

Gas - Volumetric Semimicrodetermination Of Carbon: A Wet Method For Aliphatic And Cyclic Compounds, Roger P. Staiger

Chemistry Honors Papers

This 18 page thesis explains the technique and apparatus of gas-volumetric semimicrodetermination of carbon and shows the accuracy of this method.