Catalysis and Reaction Engineering Commons^™

Recent Progress In The Mechanistic Understanding Of Co2 Reduction On Copper, Matthew M Sartin, Wei Chen, Fan He, Yan-Xia Chen

Journal of Electrochemistry

In this review, we present the major developments in the understanding of the mechanisms of the electrochemical reduction of CO₂ from a historical perspective. Most of the work discussed in this review was carried out at copper electrodes, as this is the only material at which hydrocarbons are produced in reasonable quantities. The emphasis focuses on the differentiation of mechanisms for the generation of C1 and C2 products as well as factors and methods for controlling the product selectivity of CO₂ reduction. We have highlighted ambiguities, assumptions, and important methodologies, such as differential electrochemical mass spectrometry and electrochemical …

Effect Of Nitrogen Content In Catalyst Precursor On Activity Of Fen/C Catalyst For Oxygen Reduction Reaction, Zhi Yang, Ya-Yun Shen, E Zhou, Cheng-Ling Wei, Hao-Li Qin, Juan Tian

Journal of Electrochemistry

Non-noble metal catalysts with high activity and low cost have attracted increasing interest as potential catalysts for oxygen reduction reaction (ORR) to replace Pt-based catalysts. In this paper, the effect of nitrogen content in catalyst precursor on ORR activity of FeN/C catalyst was investigated by X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET) surface area and pore size distribution measurements, transmission electron microscope (TEM), thermogravimetric analysis (TGA), and rotating disk electrode (RDE) techniques. The results show that the most active catalyst was obtained by pyrolysis in argon at 1050 °C with a catalyst precursor containing 20wt% 1,10-phenanthroline, 1wt% Fe and Black Pearl 2000. …

Challenges In The Activity And Stability Of Pt-Based Catalysts Toward Orr, Tuo Zhao, Er-Gui Luo, Xian Wang, Jun-Jie Ge, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

The development of highly efficient oxygen reduction reaction (ORR) catalysts is the key to the commercialization of fuel cells, where the sluggish ORR reaction rate needs to be overcome by adjusting the intermediates adsorption energies on the catalytic surfaces. To-date, platinum (Pt)-based materials are the-state-of-the-art catalysts in terms of both activity and stability in ORR, making them the preferred choice for commercial applications. However, the high cost of Pt-based catalysts limits their widespread use, leading to massive effects paid in reducing Pt loading, improving catalyst activity and stability. This article illustrates the challenges in the ORR reaction and introduces the …

Preparations Of Nickel-Iron Hydroxide/Sulfide And Their Electrocatalytic Performances For Overall Water Splitting, Hang-Shuo Lu, Xiao-Bo He, Feng-Xiang Yin, Guo-Ru Li

Journal of Electrochemistry

The Ni-Fe/Ti oxygen evolution electrode was prepared by electrodeposition on a titanium mesh substrate. Then, the as prepared Ni-Fe/Ti electrode was used to derive the Ni-Fe-S/Ti hydrogen evolution electrode through solid phase sulfuration. The effects of the molar ratio of Ni²⁺ to Fe³⁺ in the electrolyte and the amount of thiourea on the structures and electrochemical performances of Ni-Fe/Ti and Ni-Fe-S/Ti electrodes were investigated. The results show that the oxygen evolution performance of Ni-Fe/Ti electrode was first increased and then decreased with the increase of nickel ion content in the electrolyte. The Ni9Fe1/Ti electrode exhibited the best oxygen …

Preparation And Electrocatalytic Performance Of Nico2O4/Ni Foam For Hydrogen Peroxide Electrooxidation, Wei-Wei Chen, Fei-Fan Zhang, Jia-Liang Du, Yi Wang, Chun-Lin Zhao, Kai Zhu, Dian-Xue Cao, Gui-Ling Wang

Journal of Electrochemistry

The electrodes of Ni foam supported NiCo₂O₄ nanowires were prepared by hydrothermal method, followed by a thermal treatment in air, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the NiCo₂O₄ nanowires had a diameter of about 50 nm with a length up to 3 ~ 5 μm. The catalytic performances of the Ni foam supported NiCo₂O₄ nanowires for H₂O₂ electrooxidation were studied by cyclic voltammetry and chronoamperometry. The results show that the Ni foam supported NiCo …

Research Progresses In Polymeric Proton Exchange Membranes For Fuel Cells, Xu-Po Liu, Yun-Feng Zhang, Shao-Feng Deng, De-Li Wang, Han-Song Cheng

Journal of Electrochemistry

Proton exchange membrane (PEM) is one of the key components in PEM fuel cells, which possesses the function of separating the cathode and anode, affording proton transport channels and preventing fuel permeability. The property of PEM significantly influences the performance and service life of fuel cells. Nowadays, the commercially used Nafion membranes have the shortcomings of serious fuel permeability, low proton conductivity at elevated temperature and high price, which limits the rapid development of PEM fuel cells. Therefore, it seems to be urgent to develop novel PEMs with low cost and good comprehensive properties. Polymeric proton exchange membrane is an …

Evaluation Of Capacitive Deionization Desalination Technology For Irrigation, Ziad Khalifa, Moustafa Elshafei Prof, Abdalrahman Amer, Eng, Ashraf Seleym Dr, Tamer Samir Eng

Chemical Engineering

Desalination of brackish groundwater has great potential to alleviate the problem of the limited water resources in Egypt. In this paper, we studied the desalination of brackish water for irrigation purposes using capacitive deionization (CDI) technology. We investigated a modular unit for use in greenhouses (GH). A GH for the production of tomato requires about 3.2 m3/d of water. The target CDI unit has a production capacity of 32 m3/d for irrigation of 10 greenhouses from brackish water. The paper provides an extensive simulation study to illustrate the influence of various design parameters and to unveil the CDI technology pros …

Dry And Wet Torrefaction Of Microalgal Biomass For Biochar Production As Bioenergy Sources, Yong Yang Gan

Student Works (2020-2029)

Increasing population in global and living standards have risen the consumption of global energy. Thermochemical conversion approaches hold great potential for the biomass conversion into energy applications. Among these approaches, torrefaction is a promising technique to enhance the biomass properties, making it more practical and suitable in biofuel applications. In this study, two different species of microalgae (third generation biofuel feedstock) including Chlorella vulgaris ESP-31 and FSP-E were used as feedstocks for dry and wet torrefaction. Dry torrefaction of microalgae was performed at temperatures of 200, 250 and 300 ºC, and holding times of 15, 30, 45 and 60 min, …

First-Principle Study On The Interaction Of Ligands With Gold And Effects On Catalytic Activities, Xun Cheng

LSU Doctoral Dissertations

The extensive use of fossil fuels has increased the atmospheric concentration of CO₂, resulting in global climate change. One way to mitigate the CO₂ challenge is to convert it into useful chemicals electrocatalytically using renewable energies. Recent studies suggest that ligand-modified gold electrodes can enhance the Faradaic efficiency (FE) and selectivity of the electrochemical CO₂ reduction reaction (CO₂RR). This theoretical research, primarily based on density functional theory (DFT), has been carried out to understand the interactions of ligands with Au and possible effects on electrocatalytic activities. We systematically modeled and studied the adsorption of …

Nanoscale Colocalization Of Fluorogenic Probes Reveals The Role Of Oxygen Vacancies In The Photocatalytic Activity Of Tungsten Oxide Nanowires, Meikun Shen, Tianben Ding, Steven T. Hartman, Fudong Wang, Christina Krucylak, Zheyu Wang, Che Tan, Bo Yin, Rohan Mishra, Matthew D. Lew, Bryce Sadtler

Electrical & Systems Engineering Publications and Presentations

Defect engineering is a strategy that has been widely used to design active semiconductor photocatalysts. However, understanding the role of defects, such as oxygen vacancies, in controlling photocatalytic activity remains a challenge. Here, we report the use of chemically triggered fluorogenic probes to study the spatial distribution of active regions in individual tungsten oxide nanowires using super-resolution fluorescence microscopy. The nanowires show significant heterogeneity along their lengths for the photocatalytic generation of hydroxyl radicals. Through quantitative, coordinate-based colocalization of multiple probe molecules activated by the same nanowires, we demonstrate that the nanoscale regions most active for the photocatalytic generation of …

Aqueous And Oil Products From Hydrothermal Liquefaction Of Manure Digestate, Kenzie Burns

Honors Theses

Hydrothermal liquefaction is a promising thermochemical waste-to-energy (WtE) technology for conversion of wet biomasses, such as manure and digested manure, into value-added products, namely energy-rich biofuel and a nutrient-rich aqueous product. WtE technologies can address environmental issues relating to overproduction of organic wastes and increasing dependence on fossil fuels, which leads to climate change. HTL has not been implemented on a commercial scale, in part due to the uncertainty regarding specific reaction pathways for different feedstocks and ideal conditions for production of the most valuable products.

This research investigates the compositions of the aqueous and oil products from HTL of …

Application Of Immobilized Palladium Monolithic Catalysts In Suzuki-Miyaura And Tsuji-Wacker Redox Reactions, Sajjad Ghobadi

Theses and Dissertations

Herein, a wholistic analysis of the viability of monolithic catalysts for redox reactions is presented. The interdisciplinary approach taken in this systematic study included preparation and investigation on Pd-on-carbon monoliths as catalysts in a flow and electrochemical settings.

The Suzuki-Miyaura reaction-focused study led to rational design, preparation, and successful application of Pd⁰-on-graphene oxide (GO) monolithic catalysts in flow conditions. In this study a combination of chemical reduction, freeze-casting, and vapor-phase reduction processes was applied to Pd-GO structures leading to the preparation of these monoliths. The Suzuki flow synthesis reactions revealed that the monolithic structure led to significantly improved …

Tuning The Activity And Stability Of Platinum Nanoparticles Toward The Catalysis Of The Formic Acid Electrooxidation, Islam M. Al-Akraa, Bilquis A. Al-Qodami, Santosh Sridhar Mysore Dr, R. Viswanatha Dr, Abdul Kareem Thottoli, Ahmad M. Mohammad

Chemical Engineering

No abstract provided.

Synthesis And Characterization Of Chitosan Based Catalyst For Catalysis Applications, Mostafa Radwan

Chemical Engineering

In this research, chitosan based catalyst synthesis and characterization was investigated for different application in catalysis as chitosan based catalyst was combined with metal oxides in order to be used in dye removal of methyl orange (MO). Diluted acetic acid was used to dissolve chitosan then different percentages for metallic ions were mixed with diluted chitosan and then, 500 μL were added to the sample to reduce the metal salts then, microwave was used to heat the mixture for 5 minutes and then dried at 80-100 °C. Finally, X- ray diffraction was used to confirm the catalyst prepared. The aim …

Enhanced Glucose Electrooxidation At Ni-Cu Binary Oxide Nanocatalyst, Islam M. Al-Akraa, Mahmoud M. Abouzaid Eng, Yaser M. Asal Mr, Ahmad M. Mohammad Prof

Chemical Engineering

The aim of this study is to fabricate a nickel (NiOx) and copper (CuOx) oxide nanocatalyst on a glassy carbon (GC) electrode (will be abbreviated as Ni-Cu/GC) for glucose oxidation (GO). A sequential electrodepositon mode was applied to assemble NiOx and CuOx in the fabrication scheme. The optimization of Ni loading on the GC surface (will be abbreviated as Ni/GC electrode) was achieved first to attain the maximum catalytic efficiency in terms of the specific current toward GO. This (409 Ag1)was obtained by applying 15 mC/cm2 in the deposition of Ni. However, unfortunately the NiOx/GC could not support a long-term …

Effect Of The Electrodeposition Potential Of Platinum On The Catalytic Activity Of A Pt/Gc Catalyst Toward Formic Acid Electro−Oxidation, Islam M. Al-Akraa, Bilquis A. Al-Qodami Ms., Ahmad M. Mohammad Prof

Chemical Engineering

The electrocatalytic activity of platinum (Pt)–modified glassy carbon (GC) (referred as Pt/GC) electrodes toward the formic acid electro−oxidation (FAO) was investigated. The Pt deposition on the GC substrate was carried out by a potentiostatic technique at different potentials (from 0.2 V to −0.2 V vs. Hg/Hg2Cl2/KCl (sat.) reference electrode) and the corresponding influence on the catalytic activity toward FAO was monitored. The electrocatalytic inspection revealed a potential role for the Pt deposition potential in boosting the catalytic efficiency of the catalyst toward FAO and further in mitigating the CO poisoning that eventually deactivate the catalyst. Interestingly, the highest activity toward …

Ni-Au Anodic Nano-Electrocatalyst For Direct Glucose Fuel Cells, Islam M. Al-Akraa, Aya S. Abdulhalim Eng, Yassr M. Asal Mr, Ahmad M. Mohammad Prof

Chemical Engineering

This study aims at the sequential assembling of a nickel oxide (NiOx: cauliflower-like nanostructure, 90 nm) and gold (Au; spherical, 95 nm in an average particle size) onto the GC surface nanocatalyst on a glassy carbon (GC) electrode (will be abbreviated as Ni-Au/GC) for the glucose electro−oxidation (GO); the principal anodic reaction in the direct glucose fuel cells (DGFCs). The charge of the Ni deposition on the GC surface (will be abbreviated as Ni/GC electrode) was initially optimized to obtain the highest catalytic activity toward GO which attained at (339.8 Ag−1) by applying 15 mC in the Ni deposition. Yet, …

Review Of Established And Emergent Methods For The Production Of C4 Olefins, James Matthew Koval

Graduate Theses, Dissertations, and Problem Reports (ETD)

Current production of C₄ olefins is dominated by naphtha cracking and butane dehydrogenation, but significant research interest is developing in alternate feedstocks due to an abundance of inexpensive natural gas and bioethanol. The current C₄ olefin production methods are costly, make use of already-depleted petroleum resources, and are often hazardous to workers, which forms the impetus for investigation into alternative methods and assessment of their viability as a future means of olefin production. Methods of natural gas conversion to higher order hydrocarbons are discussed, including Fischer-Tropsch synthesis and oxidative methane coupling, each of which could form the first …

Reactions At The Critical Point Of Solution, Jason Mote

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

A Spin-Coated Tiox/Pt Nanolayered Anodic Catalyst For The Direct Formic Acid Fuel Cells, Islam M. Al-Akraa, Ahmad M. Mohammad Prof

Chemical Engineering

The CO poisoning of the platinum anodic catalyst which typically functions the catalytic deterioration of the direct formic acid fuel cells could be minimized with a simple modification for Pt with titanium oxide. The fabrication scheme involved the spin-coating of a Ti precursor onto a Pt thin layer that was physically sputtered onto a Si substrate. The whole assembly was subjected to a post-annealing processing to produce the TiOx layer (60 nm) in a porous structure (mostly Anatase) atop of the Pt surface. The porous nature of the TiOx layer permitted the participation of Pt in the electrocatalysis of the …

Development Of Novel Adsorbent For Industrial Waste Water Treatment, Hassaan M. Shehata, Dalia A. Ali, Islam M. Al-Akraa Dr, Hany A. Elazab, Hoda A. Elsawy Dr

Chemical Engineering

The main objective of this research project is to perform some experimental procedures to inform the ability of the novel adsorbent used in this project. The chemical modification of the adsorbent is the chemical oxidation of pure powder chitosan using some specific redox pairs which are potassium dichromate and sodium bisulphite. After preparing the modified chitosan, there are some parameters that must be discussed during the adsorption process. The first parameter is the time parameter, showing experimentally the optimum time for adsorption under certain conditions by collecting values of absorbance and concentration of thymol blue adsorbed after the process from …

Synthesis, Characteristic And Application Of Mesocellular Foam Carbon (Mcf-C) As Catalyst For Dehydrogenation Of Ethanol, Yoottapong Klinthongchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to investigate the synthesis of MCF-C as catalyst for dehydrogenation of ethanol. The study was classified into 3 parts. In the first part, the mesocellular foam silica (MCF-Si) was converted to mesocellular foam carbon using a surfactant residue as a carbon source, and followed by testing the dehydrogenation of ethanol to acetaldehyde. Surfactant residue in the inside of MCF-Si could be used as the carbon source for MCF-C synthesis. The obtained material could maintain the meso-structure, and exhibited higher activity for ethanol dehydrogenation in comparison to MCF-Si. For the second part, MCF-C was examined for 12 h …

Synthesis Of Mwcnts By Chemical Vapor Deposition From Methane Using Femo/Mgo Catalyst : Role Of Hydrogen And Kinetic Study, Chawalkul Chotmunkhongsin

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, carbon nanotubes (CNTs) were synthesized by chemical vapor deposition (CCVD) of methane over FeMo/MgO catalyst in a fixed-bed reactor. The role of hydrogen on CNTs synthesis and kinetics of CNTs formation were experimentally investigated. The study revealed that hydrogen in the catalyst reduction process plays an important role in the structural changes of FeMo/MgO catalyst. The catalyst structure fully transformed into metallic FeMo, resulting in the increased yield of 5 folds higher than the non-reduced catalyst. However, the slightly larger diameter and lower crystallinity ratio of CNTs was obtained. The hydrogen co-feeding during the synthesis can slightly …

Bimetallic Nanoparticles Integrated Membranes For Groundwater Remediation: Synthesis, Characterization And Applications, Hongyi Wan

Theses and Dissertations--Chemical and Materials Engineering

The detoxification of chlorinated organics from groundwater, such as trichloroethylene (TCE), tetrachloroethylene (PCE), polychlorinated biphenyl (PCB) and carbon tetrachloride (CTC), is a challenging area. Reductive dechlorination has been investigated using iron and iron-based nanoparticles, such as bare Fe, sulfidized Fe (S-Fe) and palladized Fe (Pd-Fe). However, issues including particle agglomeration, difficulties in recycling and particle leaching have been reported to hinder the application and wide usage of these techniques. The integration of nanoparticles and membranes can address these issues because of the large surface area, stability, and the potential for versatile functionalities. In this study, commercial polyvinylidene difluoride (PVDF) microfiltration …

Characterization And Electrochemical Performance Of Dopamine-Sensitized Titania Thin Films, Joshua Garay

Theses and Dissertations--Chemical and Materials Engineering

Sensitization of mesoporous titania films with dopamine and polydopamine for visible light photoelectrochemical activity is investigated. Sensitization effectiveness is compared with 8 mM dopamine solutions of varying pH (acidic, basic, and neutral), as well as with a basic polydopamine solution. Vibrational changes due to dopamine attachment are determined from detached powders by Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) is used to quantify organics attached. X-ray photoelectron spectroscopy (XPS) of intact films probes the chemically induced charge shift from dopamine attachment. Cyclic voltammetry identifies the irreversible dopamine oxidation and tin reduction voltages. Finally, chronoamperometric curves are used to compare …

Nanostructured Metal Thin Films As Components Of Composite Membranes For Separations And Catalysis, Michael J. Detisch

Theses and Dissertations--Chemical and Materials Engineering

Novel metallic thin film composite membranes are synthesized and evaluated in this work for improved separations and catalysis capabilities. Advances in technology that allow for improved membrane performance in solvent separations are desirable for low molecular weight organic separation applications such as those in pharmaceutical industries. Additionally, the introduction of catalytic materials into membrane systems allow for optimization of complex processes in a single step. By adding a nanostructured metallic thin film to its surface, a polymer membrane may be modified to exhibit these improved properties. Using magnetron sputtering, thin metal films may be deposited on commercially available membranes to …

The Development Of Temperature And Ph Responsive Hydrogels And Membranes For Selective Sorption Of Perfluoroorganics And Nanoparticle Integrated Catalytic Degradation Of Pcb, Anthony Saad

Theses and Dissertations--Chemical and Materials Engineering

The functionalization and use of responsive and catalytic polymeric membranes and materials were explored for contaminant capture and degradation. While membranes have a wide variety of uses across multiple industries, the inclusion of materials that are temperature and pH responsive in the membrane pore domain yields a wide range of applications and possibilities for water treatment. Temperature and pH responsive polymers, as well as controlled nanostructured materials, were synthesized in membrane pores for advanced adsorption-desorption and catalytic treatment of emerging organic contaminants in water. In this study, supported by the NIEHS, poly-N-isopropylacrylamide (PNIPAm) was used as a model thermo-responsive polymer, …

Deactivation Of Pdni Catalyst On Nanoporous Carbon Support Derived From Cattail Leaves In Synthesis Of Partially Hydrogenated Biodiesel(H-Fame), Tripob Longprang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, biodiesel is an alternative energy that is widely used to replace fossil fuels because of its high heat value comparable to fossil fuels. Biodiesel was easily oxidized within air. It is commonly blended with diesel fuel to have the proper properties and increase shelf life. Partial hydrogenation is one of the processes used to enhance the properties of biodiesel. In this research, bimetallic PdNi on nanoporous carbon (NPC) support derived from cattail leaves was successfully synthesized via hydrothermal carbonization and chemical activation. The prepared nanoporous carbon has a high surface area of ​​2002 m2g-1, obtained by activation process with …

Deoxygenation Of Palm Fatty Acid Distillate To Green Diesel Over Molybdenum Nitride And Carbide-Based Catalysts In A Trickle-Bed Reactor, Wanwipa Leangsiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this present work, the deoxygenation of palm fatty acid distillate (PFAD) to green diesel over γ-Al2O3 supported bimetallic CoMo and NiMo carbide and nitride catalysts was conducted in a trickle bed reactor. The catalysts were prepared by a single-step decomposition method of mixture containing hexamethylenetetramine and corresponding metal salts in presence of hydrogen and nitrogen for carbide and nitride forms, respectively at 700 oC. The prepared catalysts were characterized by XRD, XPS, N2-sorption, SEM/EDX and TGA techniques. The catalyst performance was evaluated at a temperature of 330 °C, hydrogen pressure of 5 MPa, LHSV of 1 h−1, and H2/feed …

A Comparative Simulation Of Glycerol Steam Reforming With Foam And Conventional Pellet Catalysts In Packed Bed Reactor, Chattharika Phitchayakorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aimed to study the effect of different catalyst structures to the hydrogen production process with glycerol steam reforming in packed bed reactors via the COMSOL Multiphysics program. 2D pseudo-homogeneous steady-state model of a 6-inch diameter adiabatic reactor has been developed to describe a transport phenomenon inside the packed bed reactors with two different catalyst structures of conventional 1-inch pellet catalyst and 10-30PPI foam catalyst. The simulated results show that the novel foam catalyst improved the process performance in terms of pressure drop and hydrogen yield comparing to the conventional 1-inch pellet catalyst. The reactor packed with the conventional …