Download or read book Computationally derived Design Principles for Water Oxidation Catalysts written by Daniel R. Harper and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The water oxidation reaction can be used to produce renewable solar fuels, but efficient catalysts need to be discovered to enable its use at the industrial scale. The most active known water oxidation catalysts (WOCs) follow a common theme in chemical catalysis, relying on rare metals such as ruthenium and iridium. To discover alternatives that retain this level of activity while instead utilizing earth-abundant metals, tools need to be developed which leverage knowledge from computation and from existing systems to accelerate catalyst design. This thesis focuses on developing such tools for homogeneous transition metal complexes (TMCs), which are a promising for catalyst development because their properties can be finely tuned through precise ligand modification. To understand the underlying properties which drive water oxidation, we begin by studying the TMCs with the highest activity known thus far: ruthenium WOCs. By leveraging results from density functional theory (DFT), we identify a computational descriptor which correlates well with experimentally observed activity among these catalysts. This descriptor provides a link between computation and experiment, enabling in silico screening for novel WOCs, but it alone is not sufficient. Machine learning (ML) can be used in combination with DFT to further accelerate virtual screening and to extract chemical meaningful design criteria. To enable ML for our application, we next propose a new featurization method which more readily encodes known chemical trends. Our new featurization method, eRAC-185, demonstrates improved performance on data sets which simultaneously incorporate 4d metals, which are common in catalysis, and 3d metals, which are significantly more abundant. Together, our descriptor and featurization method provide the foundation for the computationally accelerated discovery of more active WOCs with earth-abundant metals.
Download or read book In Silico Study of Reaction Mechanisms and Design Principles for Water Oxidation Catalysts written by José Luis Vallés Pardo and published by . This book was released on 2012 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Water Oxidation Catalysis written by Antoni Llobet and published by John Wiley & Sons. This book was released on 2014-04-14 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalytic water splitting is a promising strategy for capturing energy from the sun by coupling light harvesting and the oxidation of water, in order to create clean hydrogen fuel. Thus a deep knowledge of the water oxidation catalysis field is essential to be able to come up with useful energy conversion devices based on sunlight and water splitting. Molecular Water Oxidation Catalysis: A Key Topic for New Sustainable Energy Conversion Schemes presents a comprehensive and state-of-the-art overview of water oxidation catalysis in homogeneous phase, describing in detail the most important catalysts discovered today based on first and second row transition metals. A strong emphasis is placed on the description of their performance, as well as how they work from a mechanistic perspective. In addition, a theoretical description of some of the most relevant catalysts based on DFT are presented, as well as a description of related natural systems, such as the oxygen evolving system of photosystem II and the heme chlorite-dismutase. This book is a valuable resource for researchers working on water oxidation catalysis, solar energy conversion and artificial photosynthesis, as well as for chemists and materials scientists with a broad interest in new sustainable energy conversion schemes.
Download or read book Rational Design of Molecular Water Oxidation Catalysts written by Joeri Hessels and published by . This book was released on 2020 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Studies on Homogeneous Water Oxidation Catalysts written by Ge Li and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Investigations of Biomimetic Co II based Water Oxidation Catalysts written by Florian H. Hodel and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Principles of Water Oxidation and O2 based Hydrocarbon Transformation by Multinuclear Catalytic Sites written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract The central thrust of this integrated experimental and computational research program was to obtain an atomistic-level understanding of the structural and dynamic factors underlying the design of catalysts for water oxidation and selective reductant-free O2-based transformations. The focus was on oxidatively robust polyoxometalate (POM) complexes in which a catalytic active site interacts with proximal metal centers in a synergistic manner. Thirty five publications in high-impact journals arose from this grant. I. Developing an oxidatively and hydrolytically stable and fast water oxidation catalyst (WOC), a central need in the production of green fuels using water as a reductant, has proven particularly challenging. During this grant period we have designed and investigated several carbon-free, molecular (homogenous), oxidatively and hydrolytically stable WOCs, including the Rb8K2[{Ru4O4(OH)2(H2O)4}([gamma]-SiW10O36)2]·25H2O (1) and [Co4(H2O)2([alpha]-PW9O34)2]10- (2). Although complex 1 is fast, oxidatively and hydrolytically stable WOC, Ru is neither abundant nor inexpensive. Therefore, development of a stable and fast carbon-free homogenous WOC, based on earth-abundant elements became our highest priority. In 2010, we reported the first such catalyst, complex 2. This complex is substantially faster than 1 and stable under homogeneous conditions. Recently, we have extended our efforts and reported a V2-analog of the complex 2, i.e. [Co4(H2O)2([alpha]-VW9O34)2]10- (3), which shows an even greater stability and reactivity. We succeeded in: (a) immobilizing catalysts 1 and 2 on the surface of various electrodes, and (b) elucidating the mechanism of O2 formation and release from complex 1, as well as the Mn4O4L6 "cubane" cluster. We have shown that the direct O-O bond formation is the most likely pathway for O2 formation during water oxidation catalyzed by 1. II. Oxo transfer catalysts that contain two proximal and synergistically interacting redox active metal centers in the active site form another part of considerable interest of our grant because species with such sites [including methane monooxygenase (MMO) and more] are some of the most effective oxygenase catalysts known. Our team conducted the following research on [gamma]-M2-Keggin complexes: (a) investigated stability of the trimer [{Fe3(OH)3(H2O)2}3([gamma]-SiW10O36)3]15-, 4, in water, and developed the chemistry and catalysis of the di-iron centered POM, [[gamma](1,2)-SiW10{Fe(OH)}2O38]6-, 5, in organic solvents (Figure 2). We also study the thermodynamic and structural stability of [gamma]-M2-Keggin in aqueous media for different M's (d-electron metals). We have defined two structural classes of POMs with proximally bound d-electron metal centers. We refer to these structural isomers of the {[gamma]-M2SiW10} family of POMs as "in-pocket" and "out-of pocket". We have elucidated the factors controlling the structure and stability of the V, Fe, Ru, Tc, Mo and Rh derivatives of [(SiO4)M2(OH)2W10O32]4- using a range of computational tools. We have: (a) demonstrated that heteroatom X in these polyanions may function as an "internal switch" for defining the ground electronic states and, consequently, the reactivity of the [gamma]-M2-Keggin POM complexes; (b) elucidated reactivity of divacant lacunary species and polyperoxotungstates (PPTs), {Xn+O4[WO(O2)2]4}n-, which could be degradation products of [gamma]-M2-Keggin complexes in aqueous media; (c) elucidated the role of the POM ligand in stabilization of {Ru2} and {(Ru-oxo)2} fragments in the reactant and product of the reaction of {[gamma]-[(Xn+O4)Ru2(OH)2W10O32]}(8-n)- (where X = Si4+, P5+ and S6+) with O2, and (d) the mechanisms of olefin epoxidation catalyzed by these di-d-transition metal substituted and divacant lacunary [gamma]-M2-Keggin complexes. III. Complementing the efforts presented above was the development of less time-consuming but reasonably accurate computational methods allowing one to explore more deeply large catalytic systems. We developed Reactive Force Fiel ...
Download or read book Computationally Probing the Performance of Hybrid Heterogeneous and Homogeneous Iridium Based Catalysts for Water Oxidation written by and published by . This book was released on 2016 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: An attractive strategy to improve the performance of water oxidation catalysts would be to anchor a homogeneous molecular catalyst on a heterogeneous solid surface to create a hybrid catalyst. The idea of this combined system is to take advantage of the individual properties of each of the two catalyst components. We use Density Functional Theory to determine the stability and activity of a model hybrid water oxidation catalyst consisting of a dimeric Ir complex attached on the IrO2(110) surface through two oxygen atoms. We find that homogeneous catalysts can be bound to its matrix oxide without losing significant activity. Hence, designing hybrid systems that benefit from both the high tunability of activity of homogeneous catalysts and the stability of heterogeneous systems seems feasible.
Download or read book Computational Efforts Towards Efficient Catalyst Design in the Space of Oxygen Electrochemistry written by Raul Abram Flores and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid-state heterogeneous catalysts enable many of the predominant chemical reactions that drive modern society, and are critical in the chemical commodities, agriculture, and energy industries. Electrocatalysis is an important subclass of catalysis which utilizes the potential difference at electrode surfaces to drive electron transfer reactions to carry out chemical transformations. Of particular interest are the electrochemical reactions involving oxygen and water, the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) which have applications in energy technologies such as fuel cell vehicles and the electrochemical production of hydrogen, a potential alternative to fossil fuel derived hydrogen fuel. The existential crisis presented by climate change compels us to decarbonize our energy infrastructure and phase out fossil fuels. Although these green electrochemical pathways, and the catalysts that drive them, have been well studied for decades, they have yet to become economically viable to compete with fossil fuels. One promising remedy is to increase the efficiency of these processes by developing new catalyst materials, and much effort has been expended in this area. Theoretical electronic structure simulations, via density functional theory, have become indispensable tools to accelerate the design of new catalyst materials by allowing for atomistic understanding of material properties. In the first part of this thesis, we demonstrate the use DFT simulations in modeling and understanding experimental catalyst systems. First, we investigate a two-dimensional metal-organic framework consisting of various metal centers (M) and a hexaaminobenzene functional unit (HAB) known as M-HAB for the ORR. Experimental and theoretical catalytic activity results for M-HAB are presented and are shown to be consistent with one another. Additionally, we show that the DFT simulations support a linker-mediated active site instead of a metal-center active site. Next, we present experiment-theory results on the OER behavior of doped iridium-oxide thin-film catalysts and thin-film catalysts of meta-stabilized Columbite IrO2. For the doped-IrO2 catalyst system, we help elucidate the role of the dopant atom on the binding of OER intermediate species. Simulations of the columbite-IrO2 system explore the facet dependence of catalytic activity and atomistic structural factors that account for this difference. In the last couple of chapters of this work, we explore machine learning and high-throughput workflow methods to continue our investigation into iridium-oxide catalysts for the OER. First, we report an active learning based crystal structure prediction algorithm for the purpose of efficiently finding stable polymorphic phases of IrO2 and IrO3. We show that IrOx polymorphs predominately adopt octahedral coordination motifs and we demonstrate that the more oxidized IrO3 stoichiometries exhibit elevated activity over the more conventional IrO2. Lastly, we extend the polymorph discovery story by reporting on a high-throughput OER dataset composed of IrOx surface slab models created from the bulk polymorphs of the previous section. We report the theoretical OER activity of a structurally diverse set of 500 IrOx surfaces and show that the variation in OER adsorption energies can be readily modeled with structurally derived features, including a coordination based effective oxidation state descriptor which can be readily calculated for unrelaxed surfaces.
Download or read book A Molecular Approach for Dechiphering and Designing Cobalt Water Oxidation Catalysts written by Andy Nguyen and published by . This book was released on 2016 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Catalysis written by Aravind Asthagiri and published by Royal Society of Chemistry. This book was released on 2014 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive review of the methods and approaches being adopted to push forward the boundaries of computational catalysis.
Download or read book Nanostructured Catalysts written by Christian Hess and published by Royal Society of Chemistry. This book was released on 2011-07-22 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives a comprehensive up-to-date summary of the existing information on the structural/electronic properties, chemistry and catalytic properties of vanadium and molybdenum containing catalysts. It discusses the importance of nanoscience for the controlled synthesis of catalysts with functional properties and introduces the necessary background regarding surface properties and preparation techniques, leading from a textbook level to the current state of knowledge. Then follows an extensive survey and analysis of the existing open and patent literature - an essential knowledge source for the development of the new generation of partial oxidation catalysts. Important examples from current research on partial oxidation reactions are reviewed from experts in the field. The next chapter discusses the importance of 2- and 3-dimensional model systems for a fundamental understanding of the structure of transition metal oxide catalysts and its correlation to reactivity. Finally, an outlook on research opportunities within the area of partial oxidation reactions is presented.
Download or read book Product and Process Design Principles written by Warren D. Seider and published by John Wiley & Sons. This book was released on 2017 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The new 4th edition of Seider’s 'Product and Process Design Principles : Synthesis, Analysis and Design' covers content for process design courses in the chemical engineering curriculum, showing how process design and product design are inter-linked and why studying the two is important for modern applications. A principal objective of this new edition is to describe modern strategies for the design of chemical products and processes, with an emphasis on a systematic approach. This fourth edition presents two parallel tracks : (1) product design ("what to make"), and (2) process design ("how to make"), with an emphasis on process design. Process design instructors can show easily how product designs lead to new chemical processes. Alternatively, product design can be taught in a separate course subsequent to the process design course."--adapted from description on publisher web site.
Download or read book Carbon Dioxide Electrochemistry written by Marc Robert and published by Royal Society of Chemistry. This book was released on 2020-10-20 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: Homogeneous and Heterogeneous Catalysis
Download or read book Electrochemical Water Splitting written by Inamuddin and published by Materials Research Forum LLC. This book was released on 2019-10-25 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aiming at the generation of hydrogen from water, electrochemical water splitting represents a promising clean technology for generating a renewable energy resource. The book reviews the fundamental aspects and describes recent research advances. Properties and characterization methods for various types of electrocatalysts are discussed, including noble metals, earth-abundant metals, metal-organic frameworks, carbon nanomaterials and polymers. Keywords: Electrochemical Water Splitting, Renewable Energy Resource, Electrocatalysts, Oxygen Evolution Reaction (OER), Noble Metal Catalysts, Earth-Abundant Metal Catalysts, MOF Catalysts, Carbon-based Nanocatalysts, Polymer Catalysts, Transition Metal-based Electrocatalysts, Fe-based Electrocatalysts, Co-based Electrocatalysts, Ni-based Electrocatalysts, Metal Free Catalysts, Transition-Metal Chalcogenides, Prussian Blue Analogues.
Download or read book Methods for Electrocatalysis written by Inamuddin and published by Springer Nature. This book was released on 2020-01-02 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores key parameters, properties and fundamental concepts of electrocatalysis. It also discusses the engineering strategies, current applications in fuel-cells, water-splitting, metal-ion batteries, and fuel generation. This book elucidates entire category viewpoints together with industrial applications. Therefore, all the sections of this book emphasize the recent advances of different types of electrocatalysts, current challenges, and state-of-the-art studies through detailed reviews. This book is the result of commitments by numerous experts in the field from various backgrounds and expertise and appeals to industrialists, researchers, scientists and in addition understudies from various teaches.
Download or read book Advanced Oxidation Processes for Water and Wastewater Treatment written by Simon Parsons and published by IWA Publishing. This book was released on 2004-03-01 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The suitability of Advanced Oxidation Processes (AOPs) for pollutant degradation was recognised in the early 1970s and much research and development work has been undertaken to commercialise some of these processes. AOPs have shown great potential in treating pollutants at both low and high concentrations and have found applications as diverse as ground water treatment, municipal wastewater sludge destruction and VOCs control. Advanced Oxidation Processes for Water and Wastewater Treatment is an overview of the advanced oxidation processes currently used or proposed for the remediation of water, wastewater, odours and sludge. The book contains two opening chapters which present introductions to advanced oxidation processes and a background to UV photolysis, seven chapters focusing on individual advanced oxidation processes and, finally, three chapters concentrating on selected applications of advanced oxidation processes. Advanced Oxidation Processes for Water and Wastewater Treatment will be invaluable to readers interested in water and wastewater treatment processes, including professionals and suppliers, as well as students and academics studying in this area. Dr Simon Parsons is a Senior Lecturer in Water Sciences at Cranfield University with ten years' experience of industrial and academic research and development.
