Theoretical and Experimental Aspects of Electrocatalysis of the Oxygen Reduction Reaction and Related Systems

Theoretical and Experimental Aspects of Electrocatalysis of the Oxygen Reduction Reaction and Related Systems PDF Author: Nicholas Stefan Georgescu
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages : 208

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Book Description
This thesis addresses theoretical aspects of systems of relevance to energy conversion, energy storage and the nitrogen cycle, as studied by rotating disk and ring-disk electrode techniques. In particular, the non-linear character of Koutecky-Levich plots often reported in the literature for the oxygen reduction reaction, ORR, and the hydrogen peroxide reduction, HPRR, have been ascribed to the interplay between mass transport of intermediates away from the electrode surface and electrode kinetics. Also assessed was the validity of XH2O2 , a popularfigure of merit used to rank the efficacy of electrocatalysts towards the ORR. In another set of studies, numerical simulations were performed to determine the amount of superoxide produced at the disk of a rotating ring-disk electrode as detected by a functionalized concentric ring electrode.Also examined were systems involving partially-active surfaces involving in one case bromide adsorbed on Pt as a poisoning species for the ORR and HPR and bromide adsorption on Au as an electrocatalyst for the reduction of hexaaquairon(III) ion in aqueous electrolytes. In both cases, very small effects very found for bromide at small coverages. In related studies involving nanoparticles of electrocatalysts dispersed on otherwise inert supports, a full30theoretical analysis for thin films of such materials bonded to a rotating disk electrode yielded results which support the use of a modified Koutecky-Levich equation for the determination of rate constants for first order reactions.Finally, two further reactions of interest were studied, namely the bromide-bromine- tribromide reaction couple, where it was accurately predicted that negligible effects on the current would result from the formation of tribromide, as well as the reduction of hydroxylamine on adsorbed hemin on glassy carbon, for which a model was proposed that could account semiquantitatively for data collected with a RDE. Lastly, theoretical aspects of ohmic microscopy were investigated that served to validate interpretation of experimental data in terms of a primary current distribution.

Theoretical and Experimental Aspects of Electrocatalysis of the Oxygen Reduction Reaction and Related Systems

Theoretical and Experimental Aspects of Electrocatalysis of the Oxygen Reduction Reaction and Related Systems PDF Author: Nicholas Stefan Georgescu
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages : 208

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Book Description
This thesis addresses theoretical aspects of systems of relevance to energy conversion, energy storage and the nitrogen cycle, as studied by rotating disk and ring-disk electrode techniques. In particular, the non-linear character of Koutecky-Levich plots often reported in the literature for the oxygen reduction reaction, ORR, and the hydrogen peroxide reduction, HPRR, have been ascribed to the interplay between mass transport of intermediates away from the electrode surface and electrode kinetics. Also assessed was the validity of XH2O2 , a popularfigure of merit used to rank the efficacy of electrocatalysts towards the ORR. In another set of studies, numerical simulations were performed to determine the amount of superoxide produced at the disk of a rotating ring-disk electrode as detected by a functionalized concentric ring electrode.Also examined were systems involving partially-active surfaces involving in one case bromide adsorbed on Pt as a poisoning species for the ORR and HPR and bromide adsorption on Au as an electrocatalyst for the reduction of hexaaquairon(III) ion in aqueous electrolytes. In both cases, very small effects very found for bromide at small coverages. In related studies involving nanoparticles of electrocatalysts dispersed on otherwise inert supports, a full30theoretical analysis for thin films of such materials bonded to a rotating disk electrode yielded results which support the use of a modified Koutecky-Levich equation for the determination of rate constants for first order reactions.Finally, two further reactions of interest were studied, namely the bromide-bromine- tribromide reaction couple, where it was accurately predicted that negligible effects on the current would result from the formation of tribromide, as well as the reduction of hydroxylamine on adsorbed hemin on glassy carbon, for which a model was proposed that could account semiquantitatively for data collected with a RDE. Lastly, theoretical aspects of ohmic microscopy were investigated that served to validate interpretation of experimental data in terms of a primary current distribution.

Theory and Experiment in Electrocatalysis

Theory and Experiment in Electrocatalysis PDF Author: Perla B. Balbuena
Publisher: Springer Science & Business Media
ISBN: 1441955941
Category : Science
Languages : en
Pages : 597

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Book Description
Topics in Number 50 include: " Investigation of alloy cathode Electrocatalysts " A model Hamiltonian that incorporates the solvent effect to gas-phase density functional theory (DFT) calculations " DFT-based theoretical analysis of ORR mechanisms " Structure of the polymer electrolyte membranes (PEM) " ORR investigated through a DFT-Green function analysis of small clusters " Electrocatalytic oxidation and hydrogenation of chemisorbed aromatic compounds on palladium Electrodes " New models that connect the continuum descriptions with atomistic Monte Carlo simulations " ORR reaction in acid revisited through DFT studies that address the complexity of Pt-based alloys in electrocatalytic processes " Use of surface science methods and electrochemical techniques to elucidate reaction mechanisms in electrocatalytic processes " In-situ synchrotron spectroscopy to analyze electrocatalysts dispersed on nanomaterials From reviews of previous volumes: "Continues the valuable service that has been rendered by the Modern Aspects series."--Journal of Electroanalytical Chemistry "Extremely well-referenced and very readable ... Maintains the overall high standards of the series." --Journal of the American Chemical Society.

Rotating Electrode Methods and Oxygen Reduction Electrocatalysts

Rotating Electrode Methods and Oxygen Reduction Electrocatalysts PDF Author: Wei Xing
Publisher: Elsevier
ISBN: 0444633286
Category : Technology & Engineering
Languages : en
Pages : 323

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Book Description
Rotating Electrode Methods and Oxygen Reduction Electrocatalysts provides the latest information and methodologies of rotating disk electrode and rotating ring-disk electrode (RDE/RRDE) and oxygen reduction reaction (ORR). It is an ideal reference for undergraduate and graduate students, scientists, and engineers who work in the areas of energy, electrochemistry science and technology, fuel cells, and other electrochemical systems. Presents a comprehensive description, from fundamentals to applications, of catalyzed oxygen reduction reaction and its mechanisms Portrays a complete description of the RDE (Rotating Disc Electrode)/RRDE (Rotating Ring-Disc Electrode) techniques and their use in evaluating ORR (Oxygen Reduction Reaction) catalysts Provides working examples along with figures, tables, photos and a comprehensive list of references to help understanding of the principles involved

Well-defined Nanoparticle Electrocatalysts for the Carbon Dioxide and Oxygen Reduction Reactions

Well-defined Nanoparticle Electrocatalysts for the Carbon Dioxide and Oxygen Reduction Reactions PDF Author: Jamie Allyce Trindell
Publisher:
ISBN:
Category :
Languages : en
Pages : 398

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Book Description
The lack of structurally diverse electrocatalysts having high activity and controlled selectivity has limited progress in the development of technologically relevant electrochemical transformations. The key to making progress is the synergy between experiment and theory, and particularly experimental model systems against which the efficacy of theory can be benchmarked. The goal of this dissertation is to address the persisting experimental limitations that erode the fruitfulness of this union between theory and electrocatalysis. To this end, well-defined nanoparticle electrocatalysts enabling experimental validation of theoretical predictions are reported here for the carbon dioxide and oxygen reduction reactions, respectively. First, we describe the use of ex-situ scanning transmission electron microscopy (STEM) to analyze the growth of gold nanoparticles (AuNPs) during electrocatalytic CO2 reduction (Chapter 2). Relative to citrate-capped AuNPs, dendrimer-encapsulated Au NPs (Au DENs) demonstrate significantly improved structural stability during CO2 electrolysis. This work highlights the importance of performing catalyst characterization both before and after (and, ideally, during) electrochemical measurements to identify the most accurate computational models for a given electrocatalytic system. Next, we focus on Pd-based nanoalloy catalysts for the oxygen reduction reaction (ORR). Chapter 3 details the experimental verification of PdIr nanoalloy catalysts predicted to have worse catalytic activity towards the oxygen reduction reaction (ORR) than their monometallic counterparts. Specifically, alloying Ir with Pd systematically decreases the ORR activity relative to monometallic Pd NPs. The findings of this study are significant because verifying the ability of theoretical predictions to both rule-in and rule-out potential catalysts holds the key for allowing theory to guide catalyst design. Chapter 4 reports experimental evidence of composition-dependent modulation of O-binding energies on Au [subscript x] Pd [subscript (300-x)] DENs. Specifically, electrochemical characterization identifies unique active sites on AuPd nanoalloys. The concept of surface ensembles, or the presence of unique active sites on the surface of nanoalloys, is a useful concept in theoretical models that is lacking in experimental verification. Altogether, the work described in this dissertation aims to continue to close the gap between theory and experiment in the field of electrocatalysis

Electrocatalysis

Electrocatalysis PDF Author: Richard C. Alkire
Publisher: John Wiley & Sons
ISBN: 3527680454
Category : Science
Languages : en
Pages : 315

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Book Description
Catalysts speed up a chemical reaction or allow for reactions to take place that would not otherwise occur. The chemical nature of a catalyst and its structure are crucial for interactions with reaction intermediates. An electrocatalyst is used in an electrochemical reaction, for example in a fuel cell to produce electricity. In this case, reaction rates are also dependent on the electrode potential and the structure of the electrical double-layer. This work provides a valuable overview of this rapidly developing field by focusing on the aspects that drive the research of today and tomorrow. Key topics are discussed by leading experts, making this book a must-have for many scientists of the field with backgrounds in different disciplines, including chemistry, physics, biochemistry, engineering as well as surface and materials science. This book is volume XIV in the series "Advances in Electrochemical Sciences and Engineering".

Electrocatalysis for Membrane Fuel Cells

Electrocatalysis for Membrane Fuel Cells PDF Author: Nicolas Alonso-Vante
Publisher: John Wiley & Sons
ISBN: 3527830561
Category : Technology & Engineering
Languages : en
Pages : 581

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Book Description
Electrocatalysis for Membrane Fuel Cells Comprehensive resource covering hydrogen oxidation reaction, oxygen reduction reaction, classes of electrocatalytic materials, and characterization methods Electrocatalysis for Membrane Fuel Cells focuses on all aspects of electrocatalysis for energy applications, covering perspectives as well as the low-temperature fuel systems principles, with main emphasis on hydrogen oxidation reaction (HOR) and the oxygen reduction reaction (ORR). Following an introduction to basic principles of electrochemistry for electrocatalysis with attention to the methods to obtain the parameters crucial to characterize these systems, Electrocatalysis for Membrane Fuel Cells covers sample topics such as: Electrocatalytic materials and electrode configurations, including precious versus non-precious metal centers, stability and the role of supports for catalytic nano-objects; Fundamentals on characterization techniques of materials and the various classes of electrocatalytic materials; Theoretical explanations of materials and systems using both Density Functional Theory (DFT) and molecular modelling; Principles and methods in the analysis of fuel cells systems, fuel cells integration and subsystem design. Electrocatalysis for Membrane Fuel Cells quickly and efficiently introduces the field of electrochemistry, along with synthesis and testing in prototypes of materials, to researchers and professionals interested in renewable energy and electrocatalysis for chemical energy conversion.

Electrocatalysis: Computational, Experimental, and Industrial Aspects

Electrocatalysis: Computational, Experimental, and Industrial Aspects PDF Author: Carlos Fernando Zinola
Publisher: CRC Press
ISBN: 1420045458
Category : Science
Languages : en
Pages : 668

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Book Description
Electrocatalysis applications are employed in a large number of industries worldwide, ranging from old technologies such as galvanoplasty to the most up-to-date deployments involving ultracapacitators. Recognizing electrocatalysis as a useful interfacial approach to a dynamic interdisciplinary science, Electrocatalysis: Computational, Experimental,

Electrochemical Oxygen Reduction

Electrochemical Oxygen Reduction PDF Author: Pei Kang Shen
Publisher: Springer Nature
ISBN: 9813360771
Category : Science
Languages : en
Pages : 259

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Book Description
This book discusses systematically the theoretical research and the applications of electrochemical oxygen reduction. Oxygen reduction reaction is a common issue in electrochemistry, but is also an important process involved in the field of energy, cryogenic fuel cells, metal–air cells, oxygen sensors and hydrogen peroxide preparation. This book is divided into 6 chapters; it starts with a description of dynamic mechanisms, followed by a detailed introduction on the related experimental methods and related catalyst preparation technology. By providing the basic methods and testing techniques, and by demonstrating their applications, it helps readers gain a better understanding of oxygen reduction reactions, making it a valuable resource for the industrialization of scientific research achievements. Accordingly, the book appeals to a broad readership, particularly graduate students, those working at universities and research organizations, and industrial researchers.

Electrocatalysts for Fuel Cells and Hydrogen Evolution

Electrocatalysts for Fuel Cells and Hydrogen Evolution PDF Author: Abhijit Ray
Publisher: BoD – Books on Demand
ISBN: 1789848121
Category : Science
Languages : en
Pages : 130

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Book Description
The book starts with a theoretical understanding of electrocatalysis in the framework of density functional theory followed by a vivid review of oxygen reduction reactions. A special emphasis has been placed on electrocatalysts for a proton-exchange membrane-based fuel cell where graphene with noble metal dispersion plays a significant role in electron transfer at thermodynamically favourable conditions. The latter part of the book deals with two 2D materials with high economic viability and process ability and MoS2 and WS2 for their prospects in water-splitting from renewable energy.

PEM Fuel Cell Electrocatalysts and Catalyst Layers

PEM Fuel Cell Electrocatalysts and Catalyst Layers PDF Author: Jiujun Zhang
Publisher: Springer Science & Business Media
ISBN: 1848009364
Category : Technology & Engineering
Languages : en
Pages : 1147

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Book Description
Proton exchange membrane (PEM) fuel cells are promising clean energy converting devices with high efficiency and low to zero emissions. Such power sources can be used in transportation, stationary, portable and micro power applications. The key components of these fuel cells are catalysts and catalyst layers. “PEM Fuel Cell Electrocatalysts and Catalyst Layers” provides a comprehensive, in-depth survey of the field, presented by internationally renowned fuel cell scientists. The opening chapters introduce the fundamentals of electrochemical theory and fuel cell catalysis. Later chapters investigate the synthesis, characterization, and activity validation of PEM fuel cell catalysts. Further chapters describe in detail the integration of the electrocatalyst/catalyst layers into the fuel cell, and their performance validation. Researchers and engineers in the fuel cell industry will find this book a valuable resource, as will students of electrochemical engineering and catalyst synthesis.