Download or read book Combined Theoretical and Experimental Investigation of Hydrogen Production Catalysis written by and published by . This book was released on 2018 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: The widespread use of solar energy has been limited in part by the issue of effective storage. Water splitting is a means of converting solar energy into chemical fuel, in the form of hydrogen gas. It can be performed through both photochemical and electrochemical processes, via the two half reactions of water oxidation and proton reduction. Electrochemically, the catalyst receives electrons from an external circuit, which can be coupled to a renewable source such as a solar cell. Photochemically, a light-absorbing molecule provides an excited electron to a catalyst, which either generates oxygen or hydrogen gas. The work described herein studies both photochemical and electrochemical proton reduction using two different systems made of inexpensive transition metal and organic components. Nickel pyridine 2-thiolate (Ni(PyS)3-) (PyS=pyridinthiolate) has been demonstrated to have good stability and activity as a proton reduction catalyst. It is applied here as an electrocatalyst, due to the wealth of mechanistic information that can be obtained through electrochemical experiments. Six derivatives of Ni(PyS)3- were synthesized through uniform ligand modification to all three PyS- ligands using a series of electron rich or poor substituents. The physical properties of interest were investigated experimentally through electrochemical methods and UV-vis absorbance spectroscopy. Specifically, the desired properties for a hydrogen production catalyst are high proton affinity, quantified through the pKa, and low overpotential, quantified through E0. Each compound was also studied in depth using computational modeling of the various possible catalytic pathways. By combining the results of computational study with experimental results, mechanistic insight could be gained. The same joint theoretical and experimental methodology has been used to study the effect of non-uniform ligand modification. Four heteroleptic compounds were selected for study, two containing electron poor ligands and two containing electron rich ligands in varied ratios. What is found is that not only do the electronics of each ligand influence physical properties, but the placement of each ligand matters as well. Finally, photochemical hydrogen production was performed using polyvinylpyrrolidone (PVP)-coated carbon quantum dots (CQDs) as a photosensitizer, and nickel nanoparticles (NiNPs) as a catalyst. Total hydrogen production by CQD/NiNP composites as a function of the amount of PVP coating was investigated as well as various mechanistic and photophysical properties.

Download or read book Theoretical and Experimental Investigation of Hydrogen Production by Gasification of Biomass written by Madhukar Mahishi and published by . This book was released on 2006 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sorbent enhanced biomass gasification has the potential to produce a hydrogen rich, CO2 free and possibly tar free gas that can be sent to a fuel cell or gas turbine with minimal cleaning. Hence there is a potential to reduce the equipment needed for hydrogen production. This will lead to reduced capital and operating costs. Hence sorbent enhanced biomass gasification has the potential to become a cost effective technology for producing renewable hydrogen.

Download or read book Theoretical Investigation on Hydrogen Production Using Metal oxide Catalysts TiO2 and CeO2 written by Wenqing Li and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the Chemical Society written by and published by . This book was released on 1922 with total page 1468 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the Chemical Society written by Chemical Society (Great Britain) and published by . This book was released on 1922 with total page 1300 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Titles of chemical papers in British and foreign journals" included in Quarterly journal, v. 1-12.

Download or read book Towards Green Hydrogen Generation written by Mehmet Sankir and published by John Wiley & Sons. This book was released on 2024-10-01 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Readers will find a multidisciplinary approach elucidating all the important features of green hydrogen so that science researchers and energy engineers as well as those in economics, political science and international relations, will also find value. Energy sources and generation is the foremost concern of all governments, NGOs, and activist groups. With Green New Deals and reduced or net zero emission goals being implemented on a global scale, the quest for economic, scalable, efficient, and sustainable energy systems has reached a fever pitch. No one energy source ticks all the boxes and new energy technologies are being developed all the time as potential disruptors. Enter green hydrogen with zero emissions. Hydrogen is a rare gas in nature and is often found together with natural gas. While hydrogen is the most abundant element in the known universe, molecular hydrogen is very rare in nature and needs to be produced—and produced in large quantities, if we are serious about the Green Deal. This book has been organized into three parts to introduce and discuss these crucial topics. Part I discusses the Green Deal and the current state and challenges encountered in the industrialization of green hydrogen production, as well as related politics. Chapters in this section include how to decarbonize the energy industry with green hydrogen, and one that describes a gradual shift in the approach of hydrogen production technologies from non-renewable to renewable. Part II is devoted to carbon capturing and hydrogen. Chapters on biomass mass waste-to-hydrogen conversion and related efficient and sustainable hydrogen storage pathways, life cycle assessment for eco-design of biohydrogen factory by microalgae, and metal oxide-based carbon capture technologies are all addressed in this section. The third and final part of the book was designed to present all features of green hydrogen generation. Chapters include PEM water electrolysis and other electrolyzers, wind-driven hydrogen production, and bifunctional electrocatalysts-driven hybrid water splitting, are introduced and thoroughly discussed. Audience This book is directed to researchers and industry professionals in energy engineering, chemistry, physics, materials science, and chemical engineering, as well as energy policymakers, energy economists, and others in the social sciences.

Download or read book Sustainable Hydrogen Production written by Ibrahim Dincer and published by Elsevier. This book was released on 2016-08-05 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainable Hydrogen Production provides readers with an introduction to the processes and technologies used in major hydrogen production methods. This book serves as a unique source for information on advanced hydrogen generation systems and applications (including integrated systems, hybrid systems, and multigeneration systems with hydrogen production). Advanced and clean technologies are linked to environmental impact issues, and methods for sustainable development are thoroughly discussed. With Earth's fast-growing populations, we face the challenge of rapidly rising energy needs. To balance these we must explore more sustainable methods of energy production. Hydrogen is one key sustainable method because of its versatility. It is a constituent of a large palette of essential materials, chemicals, and fuels. It is a source of power and a source of heat. Because of this versatility, the demand for hydrogen is sure to increase as we aim to explore more sustainable methods of energy. Furthermore, Sustainable Hydrogen Production provides methodologies, models, and analysis techniques to help achieve better use of resources, efficiency, cost-effectiveness, and sustainability. The book is intellectually rich and interesting as well as practical. The fundamental methods of hydrogen production are categorized based on type of energy source: electrical, thermal, photonic, and biochemical. Where appropriate, historical context is introduced. Thermodynamic concepts, illustrative examples, and case studies are used to solve concrete power engineering problems. - Addresses the fundamentals of hydrogen production using electrical, thermal, photonic, and biochemical energies - Presents new models, methods, and parameters for performance assessment - Provides historical background where appropriate - Outlines key connections between hydrogen production methods and environmental impact/sustainable development - Provides illustrative examples, case studies, and study problems within each chapter

Download or read book Theoretical Studies in Heterogenous Catalysis written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditionally, knowledge in heterogeneous catalysis has come through empirical research. Nowadays, there is a clear interest to change this since millions of dollars in products are generated every year in the chemical and petrochemical industries through catalytic processes. To obtain a fundamental knowledge of the factors that determine the activity of heterogeneous catalysts is a challenge for modern science since many of these systems are very complex in nature. In principle, when a molecule adsorbs on the surface of a heterogeneous catalyst, it can interact with a large number of bonding sites. It is known that the chemical properties of these bonding sites depend strongly on the chemical environment around them. Thus, there can be big variations in chemical reactivity when going from one region to another in the surface of a heterogeneous catalyst. A main objective is to understand how the structural and electronic properties of a surface affect the energetics for adsorption processes and the paths for dissociation and chemical reactions. In recent years, advances in instrumentation and experimental procedures have allowed a large series of detailed works on the surface chemistry of heterogeneous catalysts. In many cases, these experimental studies have shown interesting and unique phenomena. Theory is needed to unravel the basic interactions behind these phenomena and to provide a general framework for the interpretation of experimental results. Ideally, theoretical calculations based on density-functional theory have evolved to the point that one should be able to predict patterns in the activity of catalytic surfaces. As in the case of experimental techniques, no single theoretical approach is able to address the large diversity of phenomena occurring on a catalyst. Catalytic surfaces are usually modeled using either a finite cluster or a two-dimensionally periodic slab. Many articles have been published comparing the results of these two approaches. An important advantage of the cluster approach is that one can use the whole spectrum of quantum-chemical methods developed for small molecules with relatively minor modifications. On the other hand, the numerical effort involved in cluster calculations increases rather quickly with the size of the cluster. This problem does not exist when using slab models. Due to the explicit incorporation of the periodicity of the crystal lattice through the Bloch theorem, the actual dimension of a slab calculation depends only on the size of the unit cell. In practical terms, the slab approach is mainly useful for investigating the behavior of adsorbates at medium and high coverages. Very large unit cells are required at the limit of low to zero coverage, or when examining the properties and chemical behavior of isolated defect sites in a surface. In these cases, from a computational viewpoint, the cluster approach can be much more cost effective than the slab approach. Slab and cluster calculations can be performed at different levels of sophistication: semi-empirical methods, simple ab initio Hartree-Fock, ab initio post-Hartree-Fock (CI, MP2, etc), and density functional theory. Density-functional (DF) based calculations frequently give adsorption geometries with a high degree of accuracy and predict reliable trends for the energetics of adsorption reactions. This article provides a review of recent theoretical studies that deal with the behavior of novel catalysts used for hydrodesulfurization (HDS) reactions and the production of hydrogen (i.e. catalytic processes employed in the generation of clean fuels). These studies involve a strong coupling of theory and experiment. A significant fraction of the review is focused on the importance of size-effects and correlations between the electronic and chemical properties of catalytic materials. The article begins with a discussion of results for the desulfurization of thiophene on metal carbides and phosphides, systems which have the potential to become the next generation of industrial HDS catalysts. Then, systematic studies concerned with the hydrogen-evolution reaction (HER) on extended surfaces, organometallic complexes and enzymes are presented. Finally, the reasons for the high catalytic activity of Au-CeO2 and Cu-CeO2 in the production of hydrogen through the water-gas shift reaction (CO + H2O --> H2 + CO2) are analyzed. It is shown that theoretical methods are very valuable tools for helping in the rational design of heterogeneous catalysts.

Download or read book Energy Aspects of Acoustic Cavitation and Sonochemistry written by Oualid Hamdaoui and published by Elsevier. This book was released on 2022-08-06 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy Aspects of Acoustic Cavitation and Sonochemistry: Fundamentals and Engineering covers topics ranging from fundamental modeling to up-scaled experiments. The book relates acoustic cavitation and its intrinsic energy balance to macroscopic physical and chemical events that are analyzed from an energetic perspective. Outcomes are directly projected into practical applications and technological assessments covering energy consumption, thermal dissipation, and energy efficiency of a diverse set of applications in mixed phase synthesis, environmental remediation and materials chemistry. Special interest is dedicated to the sonochemical production of hydrogen and its energetic dimensions. Due to the sensitive energy balance that governs this process, this is seen as a "green process" for the production of future energy carriers. - Provides a concise and detailed description of energy conversion and exchange within the single acoustic cavitation bubble and bubble population, accompanying physical and chemical effects - Features a comprehensive approach that is supported by experiments and the modeling of energy concentration within the sonochemical reactor, jointly with energy dissipation and damping phenomenon - Gives a clear definition of energy efficiency metrics of industrial sono-processes and their application to the main emergent industrial fields harnessing acoustic cavitation and sonochemistry, notably for the production of hydrogen

Download or read book Fundamentals of Hydrogen Production and Utilization in Fuel Cell Systems written by Seyed Ehsan Hosseini and published by Elsevier. This book was released on 2023-07-26 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Hydrogen Production and Utilization in Fuel Cell Systems provides a comprehensive overview of the complex and interdisciplinary issues surrounding the use of hydrogen fuel cells in the global transportation system. With a particular emphasis on the commercialization and implementation of hydrogen fuel cells, the book deals with production, utilization, storage and safety, and addresses the application of fuel cells in the road, rail, maritime and aviation sectors. For each sector, the book discusses the fundamentals of fuel cells, the current technical, environmental, safety, and economic performance, the main barriers to implementation and how to address themThis book is an invaluable reference for researchers, graduate students and industry engineers across the fuel cells and transportation sector, but is also ideal for policymakers involved in the energy transition. - Offers the first account of hydrogen fuel cell systems that considers every sector: road, rail, maritime and aviation - Focuses on the practical utilization and implementation of hydrogen fuel cells in transportation systems - Summarizes the latest research and developments in hydrogen fuel cell powered transportation

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Theoretical and experimental investigation of the stability conditions of the premixed hydrogen air combustion written by Niko Samec and published by . This book was released on 1992 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrogen Production Technologies written by Mehmet Sankir and published by John Wiley & Sons. This book was released on 2017-03-20 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a comprehensive practical review of the new technologies used to obtain hydrogen more efficiently via catalytic, electrochemical, bio- and photohydrogen production. Hydrogen has been gaining more attention in both transportation and stationary power applications. Fuel cell-powered cars are on the roads and the automotive industry is demanding feasible and efficient technologies to produce hydrogen. The principles and methods described herein lead to reasonable mitigation of the great majority of problems associated with hydrogen production technologies. The chapters in this book are written by distinguished authors who have extensive experience in their fields, and readers will have a chance to compare the fundamental production techniques and learn about the pros and cons of these technologies. The book is organized into three parts. Part I shows the catalytic and electrochemical principles involved in hydrogen production technologies. Part II addresses hydrogen production from electrochemically active bacteria (EAB) by decomposing organic compound into hydrogen in microbial electrolysis cells (MECs). The final part of the book is concerned with photohydrogen generation. Recent developments in the area of semiconductor-based nanomaterials, specifically semiconductor oxides, nitrides and metal free semiconductor-based nanomaterials for photocatalytic hydrogen production are extensively discussed.

Download or read book Metals Abstracts written by and published by . This book was released on 1998-04 with total page 1176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Homogeneous Catalysts Development written by Mohammad Reza Rahimpour and published by Elsevier. This book was released on 2024-10-25 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Homogeneous Hydrogenation and Metathesis Reactions, a volume in the Advances in Catalysis series, covers hydrogenation and metathesis reactions in two separate sections. The first section is devoted to homogeneous hydrogenation reactions and related processes, including hydrogenation of alkenes, esters, olefins, etc. In the second section, the metathesis reactions of olefins, alkenes, and alkynes are presented. In addition, the industrial application of homogeneous metathesis reactions is investigated. - Includes thermodynamic and kinetic studies of homogeneous catalysts - Describes transition metal, ligand, and solvent roles in homogeneous catalysts - Explains preparation, characterization, deactivation, and regeneration of homogeneous catalysts - Presents homogeneous catalysts by clusters, carbenes, fixed metal-complexes, and liquid-liquid multiphase catalysts

Download or read book Fossil Energy Update written by and published by . This book was released on 1977 with total page 1052 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Heterogeneous Catalysis written by Yunhai Bai and published by . This book was released on 2015 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainable development requires the innovative applications of catalysis science and technology into solving environmental and energy issues. To develop novel catalytic processes, fundamental understanding of chemical reaction mechanism and catalytic materials properties is necessary. Significant progresses in electronic structure calculation methods, coupled with advances in parallel computing technology and widely available supercomputing resources, have promoted computational catalysis to a new stage. In combination with experimental techniques, first-principles based density functional theory can be employed in the atomic-scale investigation of reaction mechanisms, structures of catalytic materials and fundamental surface chemistries. The work in this dissertation provides examples for applications of density functional theory in all three areas. First, a combined theoretical calculations, reaction kinetics experiments and microkinetic modeling approach is used in the study of nitric oxide reduction by hydrogen on platinum catalysts. In particular, we predict the catalyst is highly covered by nitric oxide under realistic reaction conditions, and elucidate the reaction mechanism by explicitly incorporating nitric oxide coverage effects into first-principles calculations and microkinetic model. Second, first-principles calculations and experimental surface science techniques are employed to study structures and catalytic applications of platinum-supported ultrathin iron oxide films, and platinum and palladium supported iron oxides islands. Finally, fundamental surface chemistries regarding to kinetic and thermodynamic isotope effects of H2/D2 dissociative adsorption on twelve transition metals, and small adsorbates adsorption properties on Ni(111) are presented. Results in these two studies serve as a database for future theoretical and experimental references.