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Full-Text Articles in Chemical Engineering
A Review Of Proton Exchange Membrane Degradation Pathways, Mechanisms, And Mitigation Strategies In A Fuel Cell, Dharmjeet Madhav, Junru Wang, Rajesh Keloth, Jorben Mus, Frank Buysschaert, Veerle Vandeginste
A Review Of Proton Exchange Membrane Degradation Pathways, Mechanisms, And Mitigation Strategies In A Fuel Cell, Dharmjeet Madhav, Junru Wang, Rajesh Keloth, Jorben Mus, Frank Buysschaert, Veerle Vandeginste
Department of Chemical and Biomolecular Engineering: Faculty Publications
Proton exchange membrane fuel cells (PEMFCs) have the potential to tackle major challenges associated with fossil fuel-sourced energy consumption. Nafion, a perfluorosulfonic acid (PFSA) membrane that has high proton conductivity and good chemical stability, is a standard proton exchange membrane (PEM) used in PEMFCs. However, PEM degradation is one of the significant issues in the long-term operation of PEMFCs. Membrane degradation can lead to a decrease in the performance and the lifespan of PEMFCs. The membrane can degrade through chemical, mechanical, and thermal pathways. This paper reviews the different causes of all three routes of PFSA degradation, underlying mechanisms, their …
Thermodynamic Modeling Of Hydrogen–Water Systems With Gas Impurity At Various Conditions Using Cubic And Pc-Saft Equations Of State, Amer Alanazi, Saleh Bawazeer, Muhammad Ali, Alireza Keshavarz, Hussein Hoteit
Thermodynamic Modeling Of Hydrogen–Water Systems With Gas Impurity At Various Conditions Using Cubic And Pc-Saft Equations Of State, Amer Alanazi, Saleh Bawazeer, Muhammad Ali, Alireza Keshavarz, Hussein Hoteit
Research outputs 2022 to 2026
Hydrogen (H2) has emerged as a viable solution for energy storage of renewable sources, supplying off-seasonal demand. Hydrogen contamination due to undesired mixing with other fluids during operations is a significant problem. Water contamination is a regular occurrence; therefore, an accurate prediction of H2-water thermodynamics is crucial for the design of efficient storage and water removal processes. In thermodynamic modeling, the Peng–Robinson (PR) and Soave Redlich–Kwong (SRK) equations of state (EoSs) are widely applied. However, both EoSs fail to predict the vapor-liquid equilibrium (VLE) accurately for H2-blend mixtures with or without fine-tuning binary interaction parameters due to the polarity of …
Editors’ Choice-Examining Performance And Durability Of Anion Exchange Membrane Fuel Cells With Novel Spirocyclic Anion Exchange Membranes, Ami C. Yang-Neyerlin, Samantha Medina, Kelly M. Meek, Derek J. Strasser, Cheng He, Daniel M. Knauss, Mustain E William, Svitlana Pylypenko, Bryan S. Pivovar
Editors’ Choice-Examining Performance And Durability Of Anion Exchange Membrane Fuel Cells With Novel Spirocyclic Anion Exchange Membranes, Ami C. Yang-Neyerlin, Samantha Medina, Kelly M. Meek, Derek J. Strasser, Cheng He, Daniel M. Knauss, Mustain E William, Svitlana Pylypenko, Bryan S. Pivovar
Faculty Publications
A series of spirocyclic copolymer membranes with varying ion exchange capacities (IECs) were investigated to probe the impact of polymer properties on in situ fuel cell performance and stability. In-situ electrochemical tests and post-mortem electron microscopy analysis of cross-sectioned membrane electrode assemblies (MEAs) have been combined with voltage loss breakdown analysis to evaluate the performance and degradation of different MEAs, and to probe the catalyst morphology and electrode structure at different stages of operation. Voltage loss breakdown results show that membrane degradation and kinetic losses played only a minor role in observed performance degradation and that performance losses were primarily …
Nanomechanical Characterization Of Fuel Cell Ionomers, Jackson Goddard
Nanomechanical Characterization Of Fuel Cell Ionomers, Jackson Goddard
UCARE Research Products
Energy sustainability can be achieved by improving and adopting clean energy technologies, and a better nanoscale understanding of ionomer-catalyst layers could lead to increased efficiency of proton exchange membrane fuel cells. Samples of Nafion ( Perfluorosulfonic acid ionomer) and PFIA (Perfluoroimide acid ionomer) of varying film thickness were prepared and then studied using contact resonance force microscopy. It was determined that storage and loss modulus increase as relative humidity increases and ionomer film thickness goes below 100 nm. Furthermore, in this specific study, the similar storage and loss modulus of Nafion and PFIA could be attributed to similar backbone structure …
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
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 …
Enhanced Electro-Oxidation Of Methanol At Pt-Au Nanocatalyst For Direct Methanol Fuel Cells, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Ahmad M. Mohammad Prof
Enhanced Electro-Oxidation Of Methanol At Pt-Au Nanocatalyst For Direct Methanol Fuel Cells, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Ahmad M. Mohammad Prof
Chemical Engineering
In this investigation, a Pt-Au nanocatalyst prepared by the coelectrodeposition of Pt (PtNPs) and Au (AuNPs) nanoparticles is assembled onto a glassy carbon (GC) electrode for efficient methanol oxidation (MO). Several molar ratios between PtNPs and AuNPs have been used and the corresponding catalytic activity towards MO is tracked. The Pt1:Au1 catalyst showed the highest catalytic activity (5 times higher oxidation peak current (Ip) and a 126 mV negative shift in the onset potential (Eonset) toward MO). The catalyst’s morphology, composition and activity are investigated and the ehancement mechanism is recognized.
A Promising Modification Of Pt Surfaces With Cnts For Decreasing Poisoning Impact In Direct Methanol Fuel Cells, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Aya A. Khalifa Ms.
A Promising Modification Of Pt Surfaces With Cnts For Decreasing Poisoning Impact In Direct Methanol Fuel Cells, Islam M. Al-Akraa Dr., Yaser M. Asal Mr, Aya A. Khalifa Ms.
Chemical Engineering
Direct methanol fuel cells (DMFCs) are clean energy sources that have many applications due to the high energy density of methanol as a fuel. However, this type of fuel cells (FCs) has limitations that are preventing it from being commercialized. One such limitation is the adsorption of intermediates such as CO into the surface of the Platinum (Pt) catalyst during methanol oxidation (MO) which deactivates its active sites, where the reaction is taking place, and leads to poisoning of the electrode over the long term. In this study, multi-walled carbon nanotubes (MWCNTs) have been introduced to the Pt-modified glassy carbon …
Fabrication Of Cuox-Pd Nanocatalyst Supported On A Glassy Carbon Electrode For Enhanced Formic Acid Electro-Oxidation, Islam M. Al-Akraa Dr., Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof
Fabrication Of Cuox-Pd Nanocatalyst Supported On A Glassy Carbon Electrode For Enhanced Formic Acid Electro-Oxidation, Islam M. Al-Akraa Dr., Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof
Chemical Engineering
Formic acid (FA) electro-oxidation (FAO) was investigated at a binary catalyst composed of palladium nanoparticles (PdNPs) and copper oxide nanowires (CuOxNWs) and assembled onto a glassy carbon (GC) electrode. /e deposition sequence of PdNPs and CuOxNWs was properly adjusted in such a way that could improve the electrocatalytic activity and stability of the electrode toward FAO. Several techniques including cyclic voltammetry, chronoamperometry, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction were all combined to report the catalyst’s activity and to evaluate its morphology, composition, and structure. /e highest catalytic activity and stability were obtained at the CuOx/Pd/GC …
On The Catalytic Activity Of Palladium Nanoparticles-Based Anodes Towards Formic Acid Electro-Oxidation: Effect Of Electrodeposition Potential, Islam M. Al-Akraa Dr., Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof
On The Catalytic Activity Of Palladium Nanoparticles-Based Anodes Towards Formic Acid Electro-Oxidation: Effect Of Electrodeposition Potential, Islam M. Al-Akraa Dr., Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof
Chemical Engineering
In this investigation, the catalytic activity of palladium nanoparticles (PdNPs)-modified glassy carbon (GC) (simply noted as PdNPs/GC) electrodes towards the formic acid electro-oxidation (FAO) was investigated. The deposition of PdNPs on the GC substrate was carried out by a potentiostatic technique at different potentials and the corresponding influence on the particles size and crystal structure of PdNPs as well as the catalytic activity towards FAO was studied. Scanning electron microscopy (SEM) demonstrated the deposition of PdNPs in spherical shapes and the average particle size of PdNPs deposited at a potential of 0 V vs. Ag/AgCl/KCl(sat.) was the smallest (ca. 8 …
Development Of Tailor-Designed Gold-Platinum Nanoparticles Binary Catalysts For Efficient Formic Acid Electrooxidation, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof
Development Of Tailor-Designed Gold-Platinum Nanoparticles Binary Catalysts For Efficient Formic Acid Electrooxidation, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof
Chemical Engineering
The modification of a glassy carbon (GC) electrode with platinum (PtNPs) and gold (AuNPs) nanoparticles is targeted to fabricate efficient anodes for the electrooxidation of formic acid (FA). A proper adjustment of the deposition sequence of PtNPs and AuNPs could eventually enhance the electrocatalytic activity of the electrode in such a way that suppresses the CO poisoning effect during FA oxidation. The highest catalytic activity is obtained at the Au/Pt/GC electrode (with PtNPs firstly deposited on the GC electrode followed by AuNPs). This superb enhancement is quantified by comparing the relative ratio of the direct vs. the indirect oxidation peaks …
Methanol Electro-Oxidation On Pt-Ru Alloy Nanoparticles Supported On Carbon Nanotubes, Ang Li, Yangchuan Xing
Methanol Electro-Oxidation On Pt-Ru Alloy Nanoparticles Supported On Carbon Nanotubes, Ang Li, Yangchuan Xing
Chemical and Biochemical Engineering Faculty Research & Creative Works
Carbon nanotubes (CNTs) have been investigated in recent years as a catalyst support for proton exchange membrane fuel cells. Improved catalyst activities were observed and attributed to metal-support interactions. We report a study on the kinetics of methanol electro-oxidation on CNT supported Pt-Ru alloy nanoparticles. Alloy catalysts with different compositions, Pt 53Ru 47/CNT, Pt 69Ru 31/CNT and Pt 77Ru 23/CNT, were prepared and investigated in detail. Experiments were conducted at various temperatures, electrode potentials, and methanol concentrations. It was found that the reaction order of methanol electro-oxidation on the PtRu/CNT catalysts was consistent with what has been reported for PtRu …
Simulation Of Nanostructured Electrodes For Polymer Electrolyte Membrane Fuel Cells, Sanjeev M. Rao, Yangchuan Xing
Simulation Of Nanostructured Electrodes For Polymer Electrolyte Membrane Fuel Cells, Sanjeev M. Rao, Yangchuan Xing
Chemical and Biochemical Engineering Faculty Research & Creative Works
Aligned carbon nanotubes (CNTs) with Pt uniformly deposited on them are being considered in fabricating the catalyst layer of polymer electrolyte membrane (PEM) fuel cell electrodes. When coated with a proton conducting polymer (e.g., Nafion) on the Pt/CNTs, each Pt/CNT acts as a nanoelectrode and a collection of such nanoelectrodes constitutes the proposed nanostructured electrodes. Computer modeling was performed for the cathode side, in which both multicomponent and Knudsen diffusion were taken into account. the effect of the nanoelectrode lengths was also studied with catalyst layer thicknesses of 2, 4, 6, and 10 μm. It was observed that shorter lengths …
Effect Of Ph On Ptru Electrocatalysts Prepared Via A Polyol Process On Carbon Nanotubes, Li Ren, Yangchuan Xing
Effect Of Ph On Ptru Electrocatalysts Prepared Via A Polyol Process On Carbon Nanotubes, Li Ren, Yangchuan Xing
Chemical and Biochemical Engineering Faculty Research & Creative Works
This paper reports a study on the pH effects on the PtRu nanoparticles synthesized in a polyol process that were deposited on carbon nanotubes (CNTs) by reducing metal salts using ethylene glycol at various pHs. It was found that the nanoparticle size, composition, and catalytic activity all were sensitive to pH. the nanoparticles decreased in size as the preparation pH increased from 1.6 to 10.0, with the largest size at 2.47 nm and the smallest at 1.13 nm. an exception was found for pH at 0.7, which resulted in an average size of only 1.01 nm. Preparation pH was found …
Electrochemical Durability Of Carbon Nanotubes At 80 °C, Liang Li, Yangchuan Xing
Electrochemical Durability Of Carbon Nanotubes At 80 °C, Liang Li, Yangchuan Xing
Chemical and Biochemical Engineering Faculty Research & Creative Works
Carbon nanotubes (CNTs) have been studied as an alternative catalyst support in polymer electrolyte membrane (PEM) fuel cells. Recent studies showed that CNTs appear to be more resistant to electrochemical corrosion than carbon black (CB). in a previous study, we have demonstrated the room temperature durability of multiwalled CNTs in both non-catalyzed and catalyzed electrochemical oxidations. This paper is to report results conducted at 80 °C-an operational temperature of PEM fuel cells. It was found that multiwalled CNTs are still more resistant than CB at the elevated temperature. However, the electrochemical oxidation rate is more rapid than that at the …
Dynamic Sulfur Tolerant Process And System With Inline Acid Gas-Selective Removal For Generating Hydrogen For Fuel Cells, Surjit Randhava, W. S. Winston Ho, Richard L. Kao, Elias H. Camara
Dynamic Sulfur Tolerant Process And System With Inline Acid Gas-Selective Removal For Generating Hydrogen For Fuel Cells, Surjit Randhava, W. S. Winston Ho, Richard L. Kao, Elias H. Camara
Chemical and Materials Engineering Faculty Patents
This invention relates to a sulfur tolerant, dynamic, compact, lightweight fuel process and system that is capable of converting sulfur bearing carbonaceous fuels to hydrogen rich gases suitable for fuel cells or chemical processing applications. The process and system is based on the AHR and WGS reactions, followed by cleanup of byproduct sulfur-containing gases and carbon oxides that would otherwise poison the fuel cell electrocatalyst. Advantageously, this is accomplished via an ASMS and a methanator or an AWMR. The process and system preferably uses a special sulfur tolerant catalysts and hardware designs that enable the conversion in an energy efficient …
Development Of Novel Method For Preparation Of Pemfc Electrodes, Hansung Kim, Branko N. Popov
Development Of Novel Method For Preparation Of Pemfc Electrodes, Hansung Kim, Branko N. Popov
Faculty Publications
A method based on pulse electrodeposition technique was developed for preparation of membrane electrode assemblies (MEAs). In this approach, platinum is deposited directly on the surface of the carbon electrode. The method ensures most of the platinum to be in close contact with the membrane. Using this method it is possible to increase the Pt/C ratio up to 75 wt % near the surface of the electrode resulting in a 5 µm thick catalyst layer. The MEA prepared by pulse electrodeposition exhibits a current density of 0.33 A/cm2 at 0.8 V with platinum loading of 0.25 mg of Pt/cm …
Solvent Diffusion Model For Aging Of Lithium-Ion Battery Cells, Harry J. Ploehn, Premanand Ramadass, Ralph E. White
Solvent Diffusion Model For Aging Of Lithium-Ion Battery Cells, Harry J. Ploehn, Premanand Ramadass, Ralph E. White
Faculty Publications
This work presents a rigorous continuum mechanics model of solvent diffusion describing the growth of solid-electrolyte interfaces (SEIs) in Li-ion cells incorporating carbon anodes. The model assumes that a reactive solvent component diffuses through the SEI and undergoes two-electron reduction at the carbon-SEI interface. Solvent reduction produces an insoluble product, resulting in increasing SEI thickness. The model predicts that the SEI thickness increases linearly with the square root of time. Experimental data from the literature for capacity loss in two types of prototype Li-ion cells validates the solvent diffusion model. We use the model to estimate SEI thickness and extract …
Mathematical Modeling Of Proton‐Exchange‐Membrane Fuel‐Cell Stacks, Dhanwa Thirumalai, Ralph E. White
Mathematical Modeling Of Proton‐Exchange‐Membrane Fuel‐Cell Stacks, Dhanwa Thirumalai, Ralph E. White
Faculty Publications
No abstract provided.
A Mathematical Model Of A Hydrogen/Oxygen Alkaline Fuel Cell, Michael C. Kimble, Ralph E. White
A Mathematical Model Of A Hydrogen/Oxygen Alkaline Fuel Cell, Michael C. Kimble, Ralph E. White
Faculty Publications
A mathematical model of a hydrogen/oxygen alkaline fuel cell is presented that can be used to predict polarization behavior under various potential loads. The model describes the phenomena occurring in the solid, liquid, and gaseous phases of the anode, separator, and cathode regions, assuming a macrohomogeneous, three-phase porous electrode structure. The model calculates the spatial variation of the partial pressures of oxygen, hydrogen, and water vapor, dissolved oxygen and hydrogen concentrations, electrolyte concentration, and the solid- and solution-phase potential drops. By developing a complete model of the alkaline fuel cell, the interaction of the various transport and kinetic resistances can …