Synthesis And Characterization Of Intermetallic Compounds And Transition Metal Nitrides As High Performance Proton Exchange Membrane Fuel Cell Materials
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Synthesis And Characterization Of Intermetallic Compounds And Transition Metal Nitrides As High Performance Proton Exchange Membrane Fuel Cell Materials
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Author : Weitian Zhao
language : en
Publisher:
Release Date : 2014
Synthesis And Characterization Of Intermetallic Compounds And Transition Metal Nitrides As High Performance Proton Exchange Membrane Fuel Cell Materials written by Weitian Zhao and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014 with categories.
One of the major challenges in fuel cell technologies, particularly for Proton Exchange Membrane Fuel Cells (PEMFCs), is developing effective catalysts for use in both the anode and cathode. Ordered intermetallic compounds have shown considerable potential for fuel cell applications due to their enhanced catalytic activity, better durability and lower cost. In this work, Pd-Sn intermetallic compounds were investigated. PdSn and Pd3Sn nanoparticles were synthesized under air-free conditions and were tested for their electrochemical properties. Both materials showed poor activities in acidic environment for formic acid and methanol oxidation, but enhanced activities under basic conditions. Various electrochemical tests and structural characterization including high-resolution TEM/STEM and EDX were performed to investigate the changes in these materials that might have resulted in such performance. In this thesis, we also focus on developing stable catalyst supports for fuel cell electrodes, another topic in fuel cell research. Motivated by recent studies which revealed the potential of transition metal nitrides as high performance catalyst supports, we developed a facile synthesis of single-phase, nanocrystalline macroporous chromium nitride and chromium titanium (oxy)nitride with an inverse opal morphology. Characterization using XRD, SEM, HR-TEM/STEM, TGA and XPS is reported. Interconversion of macroporous CrN to Cr2O3 and back to CrN while retaining the inverse opal morphology was also demonstrated. iii.
Transition Metal Nitride Coated With Atomic Layers Of Pt As A Low Cost Highly Stable Electrocatalyst For The Oxygen Reduction Reaction
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Author :
language : en
Publisher:
Release Date : 2016
Transition Metal Nitride Coated With Atomic Layers Of Pt As A Low Cost Highly Stable Electrocatalyst For The Oxygen Reduction Reaction written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with categories.
Here, the main challenges to the commercial viability of polymer electrolyte membrane fuel cells are (i) the high cost associated with using large amounts of Pt in fuel cell cathodes to compensate for the sluggish kinetics of the oxygen reduction reaction, (ii) catalyst degradation, and (iii) carbon-support corrosion. To address these obstacles, our group has focused on robust, carbon-free transition metal nitride materials with low Pt content that exhibit tunable physical and catalytic properties. Here, we report on the high performance of a novel catalyst with low Pt content, prepared by placing several layers of Pt atoms on nanoparticles of titanium nickel binary nitride. For the ORR, the catalyst exhibited a more than 400% and 200% increase in mass activity and specific activity, respectively, compared with the commercial Pt/C catalyst. It also showed excellent stability/durability, experiencing only a slight performance loss after 10,000 potential cycles, while TEM results showed its structure had remained intact. The catalyst's outstanding performance may have resulted from the ultrahigh dispersion of Pt (several atomic layers coated on the nitride nanoparticles), and the excellent stability/durability may have been due to the good stability of nitride and synergetic effects between ultrathin Pt layer and the robust TiNiN support.
One Dimensional Nanostructures For Pem Fuel Cell Applications
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Author : Shangfeng Du
language : en
Publisher: Academic Press
Release Date : 2017-08-07
One Dimensional Nanostructures For Pem Fuel Cell Applications written by Shangfeng Du and has been published by Academic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2017-08-07 with Technology & Engineering categories.
One-dimensional Nanostructures for PEM Fuel Cell Applications provides a review of the progress made in 1D catalysts for applications in polymer electrolyte fuel cells. It highlights the improved understanding of catalytic mechanisms on 1D nanostructures and the new approaches developed for practical applications, also including a critical perspective on current research limits. The book serves as a reference for the design and development of a new generation of catalysts to assist in the realization of successful commercial use that have the potential to decarbonize the domestic heat and transport sectors. In addition, a further commercialization of this technology requires advanced catalysts to address major obstacles faced by the commonly used Pt/C nanoparticles. The unique structure of one-dimensional nanostructures give them advantages to overcome some drawbacks of Pt/C nanoparticles as a new type of excellent catalysts for fuel cell reactions. In recent years, great efforts have been devoted in this area, and much progress has been achieved. Provides a review of 1D catalysts for applications in polymer electrolyte fuel cells Presents an ideal reference for the design and development of a new generation of catalysts to assist in the realization of successful commercial use Highlights the progress made in recent years in this emerging field
The Synthesis And Characterization Of Nitrides And Other Non Oxide Materials
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Author : Mark Stuart Bailey
language : en
Publisher:
Release Date : 2005
The Synthesis And Characterization Of Nitrides And Other Non Oxide Materials written by Mark Stuart Bailey and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2005 with categories.
Synthesis And Characterization Of Transition Metal Nitride And Selenide Nanocrystals And Heterostructures
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Author : Robert William Lord
language : en
Publisher:
Release Date : 2021
Synthesis And Characterization Of Transition Metal Nitride And Selenide Nanocrystals And Heterostructures written by Robert William Lord and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with categories.
The properties of nanomaterials are intimately dependent on their size, morphology, composition both elemental and structural, as well as their crystal structure or atomic arrangement. There exists a fundamental need to develop methods to precisely control and tune these parameters in order to target desirable materials. Colloidal chemistries utilize wet chemical precursors to synthesize inorganic nanomaterials from the bottom up and produce high quality materials. In addition to single component material synthesis, colloidal chemistries have been developed to synthesize multicomponent nanomaterials systems through a process called seeded growth. Seeded growth utilizes preformed nanoparticles as substrates to nucleate and grow new materials from their surfaces. This has led to the synthesis of highly complex heterostructured nanoparticles which allow for the incorporation of multiple material properties within single particle frameworks. While these techniques can control the structure and composition of the synthesized material, they do not allow for as much control over the resulting crystal structure. Other methods have been developed which allow for crystallographic templating and compositional modulation by post-synthetic cation exchange. Cation exchange utilizes molecular agents to solvate and exchange host cations in preformed crystals with those in solution while maintaining the anion sublattice relatively unperturbed. The crystallographic symmetry of the anion sublattice determines the symmetry of the final product phase. As such, cation exchange has allowed researchers to synthesize materials which are either metastable in bulk or not easily assessable through other methods. In this dissertation I discuss my efforts to utilize these synthetic tools to synthesize new and complex inorganic nanoparticles. First, I describe the seeded growth of Cu3N and Cu3PdN on Pt and Au nanocrystals. Utilizing Pt-Cu3PdN as the model system, it was observed that Cu3PdN nucleated and grew in a step-wise pathway with the initial deposition of Cu onto the surface. This was followed by the deposition of Pd onto the corners and edges of the Pt nanocubes which was followed by the coalescence and crystallization of Cu with the Pd to ultimately give Cu3PdN. When nucleating on more faceted or spherical seeds, whether Pt or Au, the resulting heterostructures took on more core@shell structures. In the absence of Pd, Cu3N nucleates indiscriminately on the surface of Pt without any of the regioselectivity seen with Cu3PdN. When utilizing Au seeds, AuCu alloy formation is observed without any apparent heterostructure formation. These observations helped us develop guidelines which are anticipated to be applicable to the formation of other ternary nitride heterostructures. Second, I discuss the synthesis of a new, metastable phase of copper selenide nanoparticles. This material was shown by EDS and XPS to adopt a nominally 2:1 stoichiometry and the XRD pattern did not match any known phase of Cu2-xSe. However, the nanoparticles did adopt a crystal structure similar to previously observed weissite Cu2-xTe. A structural model for our Cu2-xSe phase was developed utilizing a recently reported structural model for weissite Cu2-xTe which was computationally verified in collaboration with Professor Ismaila Dabo's group. Weissite-like Cu2-xSe has trigonal symmetry (space group P ̄3 m1) and is a layered structure with alternative Cu-rich and Cu-deficient layers sandwiched between layers of Se. UV-vis-NIR spectroscopy of weissite-like Cu2-xSe showed a broad plasmon absorbance band centered around 1550 nm. Lastly, I discuss my efforts to develop synthetic guidelines for the competitive synthesis of ternary copper selenide phases during their nucleation on Pt nanoparticle seeds. We showed experiments which allude to two potential synthetic pathways for the formation of CuFeSe2 and CuInSe2. It was observed that the CuInSe2 forms through a multistep pathway starting with the initial nucleation of Cu2-xSe followed by the incorporation of the In3+ through a high temperature cation exchange reaction. However, CuFeSe2 was shown to most likely to form by direct nucleation. The differences in these reactions were observed when their simultaneous nucleation was attempted, where only Pt--CuIn¬Se2 formed.
Transition Metal Carbides And Nitrides Mxenes Handbook
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Author : Chuanfang Zhang
language : en
Publisher: John Wiley & Sons
Release Date : 2024-07-23
Transition Metal Carbides And Nitrides Mxenes Handbook written by Chuanfang Zhang and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2024-07-23 with Technology & Engineering categories.
A comprehensive overview of the synthesis of high-quality MXenes In Transition Metal Carbides and Nitrides (MXenes) Handbook: Synthesis, Processing, Properties and Applications, a team of esteemed researchers provides an expert review encompassing the fundamentals of precursor selection, MXene synthesis, characterizations, properties, processing, and applications. You’ll find detailed discussions of the selection of MXene members for specific applications, as along with summaries of the physical and chemical properties of MXenes, including electrical, mechanical, optical, electromechanical, electrochemical, and electromagnetic properties. The authors delve into both successful and unsuccessful synthesis examples, offering detailed explanations of various failures to facilitates a comprehensive understanding of the reasons behind unsuccessful syntheses. Additionally, they provide detailed examinations on the characterizations of MXenes, empowering readers to develop a sophisticated understanding of how to achieve optimal quality, flake size, oxidation states, and more. You’ll also find: A thorough review of common applications of MXenes, including electrochemical applications, electromagnetic interference shielding, communications devices, and more Comprehensive explorations of solution and non-solution processing of MXenes Practical discussions of the synthesis of high-quality MXene powders, colloidal solutions and flakes, including information about MXene precursors Fulsome treatments of MXene precursor selection and their impact on MXene quality Tailored to meet the needs of graduate students, researchers, and scientists in the areas of materials science, inorganic chemistry, and physical chemistry, the Transition Metal Carbides and Nitrides (MXenes) Handbook will also benefit biochemists and professionals working in drug delivery.
The Chemistry Of Transition Metal Carbides And Nitrides
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Author : S.T. Oyama
language : en
Publisher: Springer Science & Business Media
Release Date : 2012-12-06
The Chemistry Of Transition Metal Carbides And Nitrides written by S.T. Oyama and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-12-06 with Science categories.
This book arose from a symposium titled 'Transition Metal Carbides and Nitrides: Preparation, Properties, and Reactivity' organized by Jae Sung Lee, Masatoshi Nagai and myself. The symposium was part of the 1995 Congress of Pacific Rim Chemical Societies, held in Honolulu, Hawaii between December 17-22, 1995. The meeting was the first major conference to exclusively address the theme of metal carbides and nitrides, and brought together many of the major researchers in the field. Over 50 scientists and engineers reported their latest findings in five sessions of presentations and discussions. The book closely follows the topics covered in the conference: Theory of bonding Structure and composition Catalytic properties Physical properties New methods of preparation Spectroscopy and microscopy The book is unique in its coverage. It provides a general introduction to the properties and nature of the materials, but also covers their latest applications in a wide variety of fields. It should thus be of interest to both experts and nonexperts in the fields of material science, solid-state chemistry, physics, ceramics engineering, and catalysis. The first chapter gives an overview, and many of the chapters provide summaries of advanced topics. All contributions were peer-reviewed.
Design And In Situ Characterization Of Novel Nanostructured Materials For Fuel Cells
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Author : Yin Xiong
language : en
Publisher:
Release Date : 2019
Design And In Situ Characterization Of Novel Nanostructured Materials For Fuel Cells written by Yin Xiong and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with categories.
The depletion of fossil fuels and global warming require the application of highly efficient and sustainable energy conversion devices, like fuel cells. However, the sluggish kinetics of the oxygen reduction reaction (ORR) on the cathode has significantly hindered the widespread implementation of fuel cells, which stimulates the development of highly active and durable electrocatalysts. Enormous progress has been made on both precious metal and non-precious metal catalysts, including Pt/Pd alloyed nanoparticles, transition metal oxides and nitrogen doped carbon materials. In this thesis, a bifurcated strategy involving the rational design and in situ mechanistic investigation has been proposed and conducted. Via different synthetic routes, a variety of nano-structured materials has been prepared, including Pt-based structurally ordered intermetallics, core-shell structured nanoparticles with Pt surface decoration, tri-metallic spinel oxides, bimetallic organic framework (BMOF) derived carbon materials and nitrogen-doped BMOF-derived Pt-Co nanoparticles. They are featured with distinctive properties to adapt various working conditions, for the ground transportation or stationary applications, for proton exchange membrane fuel cells (PEMFCs) or alkaline exchange membrane fuel cells (AEMFCs). For example, Pt-based catalysts exhibit excellent electrocatalytic activities with a relatively high Pt utilization efficiency, making them suitable as promising candidates in the acidic electrolyte for fuel cell vehicles. Precious-metal-free catalysts demonstrate high activity, robust durability and cost effectiveness, which can be potentially applied in alkaline media for stationary applications. The in situ mechanism analysis of these materials consists of two parts: the first reveals the structural evolution of structurally ordered bimetallic intermetallics at high temperature, from both microscopic and macroscopic levels to determine the optimized synthesis condition for the Pt3Co intermetallic nanoparticles. The second part couples the electrochemical reaction with X-ray adsorption spectroscopy to elucidate the working and degradation mechanism of trimetallic oxides, which indicates the synergistic catalysis by Co and Mn, with Fe serving as the stabilizing agent. These analyses, in return, provide valuable insights for designing and optimizing related materials in the future.
Synthesis And Characterization Of Transition Metal Nitride Materials
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Author : Shalawn Kirkland Jackson
language : en
Publisher:
Release Date : 2001
Synthesis And Characterization Of Transition Metal Nitride Materials written by Shalawn Kirkland Jackson and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2001 with categories.
Nano Electrocatalyst For Oxygen Reduction Reaction
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Author : Omar Solorza Feria
language : en
Publisher: CRC Press
Release Date : 2024-06-21
Nano Electrocatalyst For Oxygen Reduction Reaction written by Omar Solorza Feria and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2024-06-21 with Science categories.
Global warming switches our reliance from fossil fuels to green, sustainable renewable energy sources. Because of its promising nature, high-efficiency nano-electrocatalysts have sparked interest in renewable energy. Hydrogen fuel cell/polymer electrolyte membrane (PEM) vehicles are the most environmentally conscious electromobility vehicles, with a high energy density and quick refuelling technology, prompting the auto industry to launch a variety of PEM fuel cell vehicles around the world. Oxygen reduction reaction (ORR) primary research interests include fuel cells and metal-air batteries. The sluggish kinetic reaction of ORR, which is responsible for the rate-limiting reaction at the PEM fuel cell cathodic system, further decreases energy efficiency. Optimising ORR for market expansion with cost-effective and efficient nano-electrocatalysts, on the other hand, remains a challenge. The book covers fundamental ORR reaction kinetics theories, tools, and techniques. It also explains the nano electrocatalysts for ORR made of noble, non-noble, and nanocarbon materials. Finally, the book explores the applications of PEM fuel cells and metal-air batteries.