Atomic Scale Modelling Of Electro Catalytic Surfaces And Dynamic Electrochemical Interfaces

Atomic-Scale Modelling of Electrochemical Systems A comprehensive overview of atomistic computational electrochemistry, discussing methods, implementation, and state-of-the-art applications in the field The first book to review state-of-the-art computational and theoretical methods for modelling, understanding, and predicting the properties of electrochemical interfaces. This book presents a detailed description of the current methods, their background, limitations, and use for addressing the electrochemical interface and reactions. It also highlights several applications in electrocatalysis and electrochemistry. Atomic-Scale Modelling of Electrochemical Systems discusses different ways of including the electrode potential in the computational setup and fixed potential calculations within the framework of grand canonical density functional theory. It examines classical and quantum mechanical models for the solid-liquid interface and formation of an electrochemical double-layer using molecular dynamics and/or continuum descriptions. A thermodynamic description of the interface and reactions taking place at the interface as a function of the electrode potential is provided, as are novel ways to describe rates of heterogeneous electron transfer, proton-coupled electron transfer, and other electrocatalytic reactions. The book also covers multiscale modelling, where atomic level information is used for predicting experimental observables to enable direct comparison with experiments, to rationalize experimental results, and to predict the following electrochemical performance. Uniquely explains how to understand, predict, and optimize the properties and reactivity of electrochemical interfaces starting from the atomic scale Uses an engaging “tutorial style” presentation, highlighting a solid physicochemical background, computational implementation, and applications for different methods, including merits and limitations Bridges the gap between experimental electrochemistry and computational atomistic modelling Written by a team of experts within the field of computational electrochemistry and the wider computational condensed matter community, this book serves as an introduction to the subject for readers entering the field of atom-level electrochemical modeling, while also serving as an invaluable reference for advanced practitioners already working in the field.

Almost every major challenge we face, from developing renewable energy technologies to designing faster and more efficient microelectronics, relies on our ability to design and manufacture new materials that address these challenges. Given the overwhelming amount of design considerations involved in creating these materials, theoretical atomistic modeling can provide key insights into the properties of materials that can be difficult or impossible to ascertain experimentally. Furthermore, the highly parallel nature of theoretical models allows us to rapidly screen for promising materials in a manner that is less time consuming and expensive than in a laboratory. By interfacing atomic-scale models with experiments, we can provide a holistic view of materials properties and effectively design new materials. In this thesis, we utilize density functional theory (DFT) to examine the catalytic properties of electronic materials on an atomic scale and develop models that allow us to relate nanoscale properties to macroscopic observables used in experiments. In particular, we utilize ab initio molecular dynamics (AIMD) to evaluate the catalytic properties the water/electrode interface for Au(100), Au(111), and Pt(111) catalysts towards the oxygen reduction reaction (ORR) in alkaline media. Our holistic approach demonstrates that the catalyst structure/composition, hydrogen bonding from water, and coverage effects from spectator species on the catalyst surface come together to determine the overall activity of these interfaces. Additionally, we present a high-throughput screening study for identifying improved metal-alloy catalysts with improved formic acid oxidation activity. Finally, we utilize DFT calculations to evaluate graphene nanoribbon growth on Ge(001) with a focus on characterizing the interactions between graphene and the Ge surface. This work provides several examples of how atomic-scale theoretical modeling can be applied to gain key insights into catalytic materials. We use a holistic approach to modeling a wide range of interactions in both electrocatalysts and electronic material systems to determine catalyst properties. In the end, we show that this approach helps us identify atomic interactions that are necessary to describe the properties of materials.

The field of computational catalysis has existed in one form or another for at least 30 years. Its ultimate goal - the design of a novel catalyst entirely from the computer. While this goal has not been reached yet, the 21st Century has already seen key advances in capturing the myriad complex phenomena that are critical to catalyst behaviour under reaction conditions. This book presents an in depth review of select methods and approaches being adopted to push forward the boundaries of computational catalysis. Each method is supported with applied examples selected by the author, proving to be a more substantial resource than the existing literature. Both existing and possible future high-impact techniques are presented. An essential reference to anyone working in the field, the bookÆs editors share more than two decades of experience in computational catalysis and have brought together an impressive array of contributors. The book is written to ensure postgraduates and professionals will benefit from this one-stop resource on the cutting-edge of the field.

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.

The wide scope covered by the 23 papers makes the collection suitable as a survey of current developments in the subject, for specialists in electrochemical surface science, newcomers to the field, or scientists working in related disciplines. The topics include computer simulation of the structure and dynamics of water near metal surfaces, the growth kinetics of phosphate films on metal oxide surfaces, anion adsorption and charge transfer on single-crystal electrodes, an electrochemical and in-situ scanning-probe microscopic study of electroactive polymers, and the temperature dependence of the growth of surface oxide films on rhodium electrodes. Annotation copyrighted by Book News, Inc., Portland, OR.

Electrocatalysis has been the cornerstone for enhancing energy efficiency, minimizing environmental impacts and carbon emissions, and enabling a more sustainable way of meeting global energy needs. Elucidating the structure and reaction mechanisms of electrocatalysts at electrode-electrolyte interfaces is fundamental for advancing renewable energy technologies, including fuel cells, and water electrolyzers, among others. One of the fundamental challenges in electrocatalysis is understanding how to activate and sustain electrocatalytic activity, under operating conditions, for extended time periods, which calls for the use of in situ/operando methods. This thesis first introduces the design and understanding of electrocatalysts for alkaline fuel cells since they enable the use of non-precious metals to catalyze the sluggish oxygen reduction reaction (ORR) at the cathode. Metal oxide-based ORR electrocatalysts, synthesized by a hydrothermal method, in particular, Mn-Co spinel nanoparticles, have demonstrated over 1 W/cm2 benchmark peak power density with a Pt-based anode and a record 200 mW/cm2 with a Ni-based anode for a completely non-precious metal-containing alkaline fuel cell, in membrane electrode assembly (MEA) measurements. Analytical scanning transmission electron microscopy (STEM) has been extensively employed to resolve the heterogeneous crystal structures and chemical environments at the atomic scale. Operando X-ray absorption spectroscopy (XAS) methods revealed that the superior performance of Mn-Co spinels in low humidity, relative to Pt, originates from synergistic effects in which the Mn sites bind O2 while the Co sites activate H2O to facilitate the proton-coupled electron transfer process. Moving beyond oxides, we have developed nitride-core oxide-shell Co4N/C and Pd-based alloys as ORR electrocatalysts for high-power alkaline fuel cells. The second part of this thesis focuses on operando studies of electrochemical interfaces. In situ heating STEM and heating X-ray diffraction were used to track the dynamic order-disorder phase transition of Pt3Co intermetallic ORR catalysts during annealing and quantify the degree of ordering as a key structural factor for long-term MEA durability. This thesis then presents the efforts to tackle a grand challenge in physical chemistry : understanding and spatially resolving the electrochemical double layer (EDL) at electrolyte/nanocrystal electrode interfaces. Preliminary studies, with heavy halide anion and/or alkali cations as chemical probes, while promising, have yet to provide compelling evidences of potential-dependent changes of ionic distributions. However, the pursuit of these EDL studies led to the unexpected observation of cathodic corrosion, an enigmatic electrochemical process in which noble metal electrodes corrode under sufficiently reducing potentials. I employed operando EC-STEM to reveal that cathodic corrosion at solid-liquid-gas interfaces yields significantly higher levels of structural degradation for nanocrystals than bulk electrodes. The dynamic evolution of morphology, composition, and structural information was retrieved by analytical and 4D-STEM. Such microscopic studies can provide unprecedented insights into the structural evolution of nanoscale electrocatalysts during electrochemical reactions under highly reducing potentials, such as CO2 and N2 reduction.

The Nobel Prize in Chemistry 2007 awarded to Gerhard Ertl for his groundbreaking studies in surface chemistry highlighted the importance of heterogeneous catalysis not only for modern chemical industry but also for environmental protection. Heterogeneous catalysis is seen as one of the key technologies which could solve the challenges associated with the increasing diversification of raw materials and energy sources. It is the decisive step in most chemical industry processes, a major method of reducing pollutant emissions from mobile sources and is present in fuel cells to produce electricity. The increasing power of computers over the last decades has led to modeling and numerical simulation becoming valuable tools in heterogeneous catalysis. This book covers many aspects, from the state-of-the-art in modeling and simulations of heterogeneous catalytic reactions on a molecular level to heterogeneous catalytic reactions from an engineering perspective. This first book on the topic conveys expert knowledge from surface science to both chemists and engineers interested in heterogeneous catalysis. The well-known and international authors comprehensively present many aspects of the wide bridge between surface science and catalytic technologies, including DFT calculations, reaction dynamics on surfaces, Monte Carlo simulations, heterogeneous reaction rates, reactions in porous media, electro-catalytic reactions, technical reactors, and perspectives of chemical and automobile industry on modeling heterogeneous catalysis. The result is a one-stop reference for theoretical and physical chemists, catalysis researchers, materials scientists, chemical engineers, and chemists in industry who would like to broaden their horizon and get a substantial overview on the different aspects of modeling and simulation of heterogeneous catalytic reactions.

Molecular surface science has made enormous progress in the past 30 years. The development can be characterized by a revolution in fundamental knowledge obtained from simple model systems and by an explosion in the number of experimental techniques. The last 10 years has seen an equally rapid development of quantum mechanical modeling of surface processes using Density Functional Theory (DFT). Chemical Bonding at Surfaces and Interfaces focuses on phenomena and concepts rather than on experimental or theoretical techniques. The aim is to provide the common basis for describing the interaction of atoms and molecules with surfaces and this to be used very broadly in science and technology. The book begins with an overview of structural information on surface adsorbates and discusses the structure of a number of important chemisorption systems. Chapter 2 describes in detail the chemical bond between atoms or molecules and a metal surface in the observed surface structures. A detailed description of experimental information on the dynamics of bond-formation and bond-breaking at surfaces make up Chapter 3. Followed by an in-depth analysis of aspects of heterogeneous catalysis based on the d-band model. In Chapter 5 adsorption and chemistry on the enormously important Si and Ge semiconductor surfaces are covered. In the remaining two Chapters the book moves on from solid-gas interfaces and looks at solid-liquid interface processes. In the final chapter an overview is given of the environmentally important chemical processes occurring on mineral and oxide surfaces in contact with water and electrolytes. Gives examples of how modern theoretical DFT techniques can be used to design heterogeneous catalysts This book suits the rapid introduction of methods and concepts from surface science into a broad range of scientific disciplines where the interaction between a solid and the surrounding gas or liquid phase is an essential component Shows how insight into chemical bonding at surfaces can be applied to a range of scientific problems in heterogeneous catalysis, electrochemistry, environmental science and semiconductor processing Provides both the fundamental perspective and an overview of chemical bonding in terms of structure, electronic structure and dynamics of bond rearrangements at surfaces