Download or read book Density Functional Theory Studies of Destabilized Metal Hydrides for Hydrogen Storage Applications written by Sudhakar Venkata Alapati and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DFT Study of Hydrogen Storage in Complex Hydrides Doped with Transition Metals written by Jiamei Yu and published by . This book was released on 2009 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, two types of complex hydrides doped with transition metals as potential hydrogen storage materials were investigated using density functional theory (DFT) calculations. TiAl3 cluster as well as its interaction with hydrogen was characterized.
Download or read book Hydrogen Storage written by Jianjun Liu and published by BoD – Books on Demand. This book was released on 2012-09-05 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen, as an energy carrier, is widely regarded as a potential cost effective, renewable, and clean energy alternative to petroleum in order to mitigate energy shortage and global climate warming issues that the world is currently facing. However, storage of hydrogen is a substantial challenge, especially for applications in vehicles with fuel cells that use proton-exchange membranes (PEMs). Therefore, scientific community has started focusing their research activities on developing advanced hydrogen storage materials through nanotechnology. The book presents a wide variety of nanostructured materials used for application in hydrogen storage, covering chemical and physical storage approaches. The research topics include computational design, synthesis, processing, fabrication, characterization, properties and applications of nanomaterials in hydrogen storage systems.
Download or read book Final Report written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen is a promising energy source for the future economy due to its environmental friendliness. One of the important obstacles for the utilization of hydrogen as a fuel source for applications such as fuel cells is the storage of hydrogen. In the infrastructure of the expected hydrogen economy, hydrogen storage is one of the key enabling technologies. Although hydrogen possesses the highest gravimetric energy content (142 KJ/g) of all fuels, its volumetric energy density (8 MJ/L) is very low. It is desired to increase the volumetric energy density of hydrogen in a system to satisfy various applications. Research on hydrogen storage has been pursed for many years. Various storage technologies, including liquefaction, compression, metal hydride, chemical hydride, and adsorption, have been examined. Liquefaction and high pressure compression are not desired due to concerns related to complicated devices, high energy cost and safety. Metal hydrides and chemical hydrides have high gravimetric and volumetric energy densities but encounter issues because high temperature is required for the release of hydrogen, due to the strong bonding of hydrogen in the compounds. Reversibility of hydrogen loading and unloading is another concern. Adsorption of hydrogen on high surface area sorbents such as activated carbon and organic metal frameworks does not have the reversibility problem. But on the other hand, the weak force (primarily the van der Waals force) between hydrogen and the sorbent yields a very small amount of adsorption capacity at ambient temperature. Significant storage capacity can only be achieved at low temperatures such as 77K. The use of liquid nitrogen in a hydrogen storage system is not practical. Perhydrides are proposed as novel hydrogen storage materials that may overcome barriers slowing advances to a hydrogen fuel economy. In conventional hydrides, e.g. metal hydrides, the number of hydrogen atoms equals the total valence of the metal ions. One LiH molecule contains one hydrogen atom because the valence of a Li ion is +1. One MgH2 molecule contains two hydrogen atoms because the valence of a Mg ion is +2. In metal perhydrides, a molecule could contain more hydrogen atoms than expected based on the metal valance, i.e. LiH1+n and MgH2+n (n is equal to or greater than 1). When n is sufficiently high, there will be plenty of hydrogen storage capacity to meet future requirements. The existence of hydrogen clusters, Hn+ (n = 5, 7, 9, 11, 13, 15) and transition metal ion-hydrogen clusters, M+(H2)n (n = 1-6), such as Sc(H2)n+, Co(H2)n+, etc., have assisted the development of this concept. Clusters are not stable species. However, their existence stimulates our approach on using electric charges to enhance the hydrogen adsorption in a hydrogen storage system in this study. The experimental and modeling work to verify it are reported here. Experimental work included the generation of cold hydrogen plasma through a microwave approach, synthesis of sorbent materials, design and construction of lab devices, and the determination of hydrogen adsorption capacities on various sorbent materials under various electric field potentials and various temperatures. The results consistently show that electric potential enhances the adsorption of hydrogen on sorbents. NiO, MgO, activated carbon, MOF, and MOF and platinum coated activated carbon are some of the materials studied. Enhancements up to a few hundred percents have been found. In general, the enhancement increases with the electrical potential, the pressure applied, and the temperature lowered. Theoretical modeling of the hydrogen adsorption on the sorbents under the electric potential has been investigated with the density functional theory (DFT) approach. It was found that the interaction energy between hydrogen and sorbent is increased remarkably when an electric field is applied. This increase of binding energy offers a potential solution for DOE when looking for a compromise between chemisorption and physisorption for hydrogen storage. Bonding of chemisorption is too strong and requires high temperature for the release of hydrogen. Bonding for the physisorption is too weak for sufficient uptake of hydrogen. Electric field potentials can enhance the physisorption and can be adjusted to yield reversibility required in a system at room temperature.
Download or read book DFT Investigations of Hydrogen Storage Materials written by Gang Wang and published by . This book was released on 2016 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Hydrogen serves as a promising new energy source having no pollution and abundant on earth. However the most difficult problem of applying hydrogen is to store it effectively and safely, which is smartly resolved by attempting to keep hydrogen in some metal hydrides to reach a high hydrogen density in a safe way. There are several promising metal hydrides, the thermodynamic and chemical properties of which are to be investigated in this dissertation. Sodium alanate (NaAlH4) is one of the promising metal hydrides with high hydrogen storage capacity around 7.4 wt. % and relatively low decomposition temperature of around 100 °C with proper catalyst. Sodium hydride is a product of the decomposition of NaAlH4 that may affect the dynamics of NaAlH4. The two materials with oxygen contamination such as OH− may influence the kinetics of the dehydriding/rehydriding processes. Thus the solid solubility of OH− groups (NaOH) in NaAlH5 and NaH is studied theoretically by DFT calculations. Magnesium boride [Mg(BH4)2] is has higher hydrogen capacity about 14.9 wt. % and the decomposition temparture [sic] of around 250 °C. However one flaw restraining its application is that some polyboron compounds like MgB12H12 preventing from further release of hydrogen. Adding some transition metals that form magnesium transition metal ternary borohydride [Mg[subscript a]TM[subscript b](BH4)[subscript c]] may simply the decomposition process to release hydrogen with ternary borides (Mg[subscript a]TM[subscript b]B[subscript c]). The search for the probable ternary borides and the corresponding pseudo phase diagrams as well as the decomposition thermodynamics are performed using DFT calculations and GCLP method to present some possible candidates"--Abstract, page iv.
Download or read book Hydrogen Storage Materials written by R. G. Barnes and published by . This book was released on 1988 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ames Laboratory, Iowa, USA
Download or read book Compendium of Hydrogen Energy written by Ram Gupta and published by Woodhead Publishing. This book was released on 2016-02-03 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compendium of Hydrogen Energy, Volume 2: Hydrogen Storage, Distribution and Infrastructure focuses on the storage and transmission of hydrogen. As many experts believe the hydrogen economy will, at some point, replace the fossil fuel economy as the primary source of the world’s energy, this book details hydrogen storage in pure form, including chapters on hydrogen liquefaction, slush production, as well as underground and pipeline storage. Other sections in the book explore physical and chemical storage, including environmentally sustainable methods of hydrogen production from water, with final chapters dedicated to hydrogen distribution and infrastructure. Covers a wide array of methods for storing hydrogen, detailing hydrogen transport and the infrastructure required for transition to the hydrogen economy Written by leading academics in the fields of sustainable energy and experts from the world of industry Part of a very comprehensive compendium which looks at the entirety of the hydrogen energy economy
Download or read book Functional Materials Based on Metal Hydrides written by Torben R. Jensen and published by MDPI. This book was released on 2018-10-18 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Functional Materials Based on Metal Hydrides" that was published in Inorganics
Download or read book Density Functional Theory DFT Study of Hydrogen Storage in Porous Silicon written by Mawla Boaks and published by . This book was released on 2018 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on plane wave DFT calculation, we carried out micro level investigation of hydrogen storage in nanoporous silicon (npSi). One quarter of a hexagonal pore with Palladium catalyst placed at the surface has been studied for hydrogen dissociation, spillover, bond hopping, and diffusion for both single catalyst atom and small catalyst cluster consisting of multiple catalyst atoms. All the DFT computations were done in one of the biggest research supercomputer facilities of the world, Big Red II. We opted ABINIT, an open source DFT tool for our computations. Our calculation revealed low dissociation, spillover, and bond hoping energy barrier. The energy required to be provided from external sources to fully recharge the storage medium from a gaseous source at a completely empty state has also been evaluated. Hydrogen diffusion along the inner surface of the pore as a means of bond hopping and the possibility of quantum tunneling, a low temperature phenomena used to spontaneously go over an otherwise less likely high energy barrier have been studied as well. Using these micro level parameter values evaluated from the DFT study, the performance of any potential hydrogen storage material can be compared to a set of characteristics sought in an efficient storage media. Thus, the micro scale feasibility of this novel npSi material based hydrogen storage technology was studied as a part of a STTR Phase I project.
Download or read book Hydrogen Storage Technology written by Lennie Klebanoff and published by CRC Press. This book was released on 2012-12-11 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zero-carbon, hydrogen-based power technology offers the most promising long-term solution for a secure and sustainable energy infrastructure. With contributions from the world’s leading technical experts in the field, Hydrogen Storage Technology: Materials and Applications presents a broad yet unified account of the various materials science, physics, and engineering aspects involved in storing hydrogen gas so that it can be used to provide power. The book helps you understand advanced hydrogen storage materials and how to build systems around them. Accessible to nonscientists, the first chapter explains how a hydrogen-based energy carrier and storage infrastructure is required to address fuel resource and political insecurities as well as global climate change. The second chapter describes high-efficiency hydrogen conversion devices, including internal combustion engines and fuel cells, for producing power and electricity. The book then dives into the state of the art in hydrogen storage technology. It covers recent hydrogen storage materials research and hydrogen storage methods, with an emphasis on solid-state techniques. It also reviews codes and standards and explores engineering approaches for creating zero-emission, hydrogen-fueled power systems. Collecting recent results from around the globe, this book gets you up to date on the latest hydrogen-based technology for mitigating energy and environmental risks. It provides a deep science and engineering-based description of hydrogen storage materials and clearly explains how the materials are engineered for zero-emission, carbon-free power systems.
Download or read book Density Functional Theory Studies of Selected Hydrogen Bond Assisted Chemical Reactions written by Zhen Guo and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Density Functional Theory Studies of Selected Hydrogen Bond Assisted Chemical Reactions" by Zhen, Guo, 郭臻, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b4218233 Subjects: Hydrogen bonding Molecular structure Water Chemical reactions - Mathematical models Density functionals
Download or read book A Cluster Density Functional Theory Study of the Interaction of the Hydrogen Storage System NaAlH4 with Transition Metal Catalysts written by Ali Awad Marashdeh and published by . This book was released on 2008 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Investigation of Hydrogen Storage Material Design by Density Functional Theory A Case Study of Amorphous Carbon written by 陳映澄 and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrides for Energy Storage written by A. F. Andresen and published by Elsevier. This book was released on 2013-10-22 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrides for Energy Storage documents the proceedings of an International Symposium held in Geilo, Norway on August 14-19, 1977. This book discusses the thermodynamics of metal, alloy and intermetallic/hydrogen systems; localization and diffusion of hydrogen in lanthanum-nickel compounds; kinetics of hydrogen absorption and desorption; and nuclear magnetic resonance studies of metal hydrides. The calculated heats of formation of metal and metal alloy hydrides; hydrogen absorption into rare earth intermetallic compounds; plateau pressure of RE Ni5 and RE Co5 hydrides; and hydride formation of C14-type Ti alloy are also elaborated. This text likewise covers the mixing effects of two different types of hydrides; hydrogen storage electrode systems; and applications of metal hydrides. This publication is intended for chemists concerned with the fundamental properties of hydrides.
Download or read book Metal Hydrides written by M. V. C. Sastri and published by . This book was released on 1998 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text addresses the wide range of technical uses of metal hydrides with a view to opening up a vision of the immense application potential.
Download or read book Theoretical and Experimental Solid State Physics written by Uko Ofe and published by LAP Lambert Academic Publishing. This book was released on 2014-10-13 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Density Functional Theory has proved to be a fast and efficient method for calculating various properties of solid insulating materials. From our studies, we have observed that calculations of the structural and electronic properties of alkali metal hydrides LiH, NaH, KH, RbH and CsH) and alkaline earth metal hydrides (BeH2, MgH2, CaH2, SrH2 and BaH2) reveal the exact problem with the description for these compounds within PBE formulation of generalized gradient approximation (GGA), which is our principal focus.Generally, for the hydrides accurate calculation of the band gap requires computationally extensive approach as GW method or time-dependent DFT. In this work, a new and more efficient method, GGA + U, which significantly improves the description of the electronic structure in DFT has been used; thus, in this proposed method, our results were in agreement with other theoretical and experimental results obtained by other investigators. GGA+U approach is based on the Hubbard model applied for exchange-correlation function to hydrogen atoms, even though the metal hydrides are not strongly correlated materials.
Download or read book Charge Density Studies of Lightweight Metal Hydrides for Hydrogen Storage written by Franklin Ngwa Che and published by . This book was released on 2013 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:
