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Rational Design Of Efficient And Durable Pt Based Electrocatalysts For Fuel Cells
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Book Synopsis Rational Design of Efficient and Durable Pt-based Electrocatalysts for Fuel Cells by : Bosi Peng
Download or read book Rational Design of Efficient and Durable Pt-based Electrocatalysts for Fuel Cells written by Bosi Peng and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proton exchange membrane fuel cells (PEMFCs) offer an attractive zero-emission power generation technology to realize a carbon-neutral future. However, the competitiveness of PEMFCs is severely constrained by the costly precious metal catalysts needed for the cathode oxygen reduction reaction (ORR). This thesis aims to address two critical challenges in ORR catalysts, activity and durability. To this end, we first developed a facile molecular surface modification approach using dimethylformamide to improve the microkinetics of the physisorption/desorption process in ORR, to achieve an unprecedented specific activity of 21.8 mA/cm2 in modified model PtCuNi catalyst. Next, by exploiting a unique design of jagged Pt nanowire catalysts, we developed a high-performance PEMFC using PtCo nanowire catalysts to realize an unprecedented mass activity of 1.06 A/mgPt, far surpassing the Department of Energy target. Lastly, exploiting a strong-metal-oxide binding effect, we further designed a unique ultrafine Pt nanocatalysts with embedded cobalt oxide to achieve superior power performance and life durability. These studies offer new perspectives on fuel cell catalyst design and hold significant promise to substantially reduce the lifetime adjusted cost for widespread adoption of PEMFCs in practical technologies.
Book Synopsis Durable Fuel Cell Electrocatalysts for Energy Conversion by : Zishuai Zhang
Download or read book Durable Fuel Cell Electrocatalysts for Energy Conversion written by Zishuai Zhang and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Electrocatalysts play an important avenue in clean and efficient energy conversion. Of the many electrocatalytic processes, the oxygen reduction reaction (ORR) attracts increasing attention due to its widespread importance in electrochemical cells. One of the most important applications is in proton-exchange membrane fuel cells (PEMFCs), which are considered as a promising power generation system because of its low operating temperature (70-90 ̊C), sustainable energy sources (hydrogen) and high energy efficiency. ORR is a key half reaction that takes place at the cathode with sluggish kinetics and requires noble metal (e.g. platinum)-based electrocatalysts to increase the reaction rate to attain practically usable levels. High cost and poor durability are major drawbacks of the commercial platinum on carbon (Pt/C) catalyst, and the corrosion of the carbon supports is considered one of the main reasons for the loss of expensive Pt, resulting in loss of performance of PEMFC. Therefore, more corrosion resistant, electrochemically stable and low-cost supports are highly desired for PEMFCs’ improved performance.Methanol oxidation reaction (MOR) is an anodic half reaction occurs at anodes of methanol fuel cells. Pt/C catalyst is also commonly used for that reaction. This thesis attempts to rationally design and synthesize various different nanostructured alternatives to carbon black for ORR and MOR. Graphene, a high conductive and stable two-dimensional carbon support, was successfully exfoliated electrochemically with little defects. Platinum (Pt) nanoparticles were deposited on graphene via double-pulse deposition technique. The catalyst was demonstrated to be highly efficient for MOR with a 920 mA/mg forward current density.Durable carbon nanotube (CNT) microspheres were synthesized through a facile and scalable ultrasonic bonding method without any binder or surfactant. The CNT microspheres with electrodeposited Pt were showcased as efficient ORR catalyst supports which showed no degradation after 12, 000 cycles (26.6 h). Furthermore, a soluble acicular calcium carbonate (aragonite, diameter 100 nm; length 800 nm) was used to created connected porosity in the microspheres to improve the mass transfer as the thickness increases. As for the ORR catalysis performance, the Pt decorated microspheres with macropores was 3.4 times higher (specific activity at 0.9V vs RHE) than non-macroporous microspheres with the identical Pt loading.Besides carbon-based supports, TiC was investigated as a potential carbon alternative due to its metallic electrical conductivity and excellent corrosion resistance. A cobalt oxide shell with high ORR activity was deposited onto TiC to improve its stability at high potential. We demonstrated that the oxide anchored Pt on TiC catalysts exhibited excellent durability (~100% catalytic activity remained at 0.1M KOH, and ~92% catalytic activity remained at 0.1M HClO4 after 16.7 h) compared to the Pt/C (~50% remained in both alkaline and acidic solutions). As assessed by transmission electron microscope (TEM), no significant Pt detachment or agglomeration was observed in oxide anchored catalysts, while heavily agglomeration has occurred to Pt/C.Hematene, two-dimensional layer of hematite (Fe2O3), has recently been exfoliated by means of liquid exfoliation. As the biodegradable metal, Fe-based materials attracts lots of attentions due to their ability to be entirely dissolved and cleared from the body. Electronics comprised of biodegradable metals can be programmed to degrade after the implantation. Here, we fabricated potentially biodegradable electrodes by using Au and hematene for glucose oxidation. It showed 9.5 mA/mgAu oxidation current density at the potential of 0.6V (vs. RHE), and high stability during the continuous cell cycling. Additionally, the prepared catalyst exhibited short response time and linear calibration range"--
Book Synopsis Electrocatalysts for Fuel Cells and Hydrogen Evolution by : Abhijit Ray
Download or read book Electrocatalysts for Fuel Cells and Hydrogen Evolution written by Abhijit Ray and published by BoD – Books on Demand. This book was released on 2018-12-05 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book starts with a theoretical understanding of electrocatalysis in the framework of density functional theory followed by a vivid review of oxygen reduction reactions. A special emphasis has been placed on electrocatalysts for a proton-exchange membrane-based fuel cell where graphene with noble metal dispersion plays a significant role in electron transfer at thermodynamically favourable conditions. The latter part of the book deals with two 2D materials with high economic viability and process ability and MoS2 and WS2 for their prospects in water-splitting from renewable energy.
Book Synopsis Electrocatalysts for Low Temperature Fuel Cells by : Thandavarayan Maiyalagan
Download or read book Electrocatalysts for Low Temperature Fuel Cells written by Thandavarayan Maiyalagan and published by John Wiley & Sons. This book was released on 2017-05-08 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: Meeting the need for a text on solutions to conditions which have so far been a drawback for this important and trend-setting technology, this monograph places special emphasis on novel, alternative catalysts of low temperature fuel cells. Comprehensive in its coverage, the text discusses not only the electrochemical, mechanistic, and material scientific background, but also provides extensive chapters on the design and fabrication of electrocatalysts. A valuable resource aimed at multidisciplinary audiences in the fields of academia and industry.
Book Synopsis Robust Platinum-based Electrocatalysts for Fuel Cell Applications by : Eric James Coleman
Download or read book Robust Platinum-based Electrocatalysts for Fuel Cell Applications written by Eric James Coleman and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer electrolyte fuel cells (PEMFCs) are energy conversion devices that exploit the energetics of the reaction between hydrogen fuel and O2 to generate electricity with water as the only byproduct. PEMFCs have attracted substantial attention due to their high conversion efficiency, high energy density, and low carbon footprint. However, PEMFC performance is hindered by the high activation barrier and slow reaction rates at the cathode where O2 undergoes an overall 4-electron reduction to water. The most efficient oxygen reduction reaction (ORR) catalyst materials to date are Pt group metals due to their high catalytic activity and stability in a wide range of operating conditions. Before fuel cells can become economically viable, efforts must be taken to decrease Pt content while maintaining a high level of ORR activity. This work describes the design and synthesis of a Pt-Cu electrocatalyst with ORR activity exceeding that of polycrystalline Pt. Production of this novel catalyst is quite simple and begins with synthesis of a porous Cu substrate, formed by etching Al from a Cu-Al alloy. The porous Cu substrate is then coated with a Pt layer via a spontaneous electrochemical process known as galvanic replacement. The Pt layer enhances the ORR activity (as measured by a rotating ring-disk electrode (RRDE)) and acts as a barrier towards corrosion of the Cu understructure. Growth of the Pt layer can be manipulated by time, temperature, concentration of Pt precursor, and convection rate during galvanic replacement. Data from analytical and electrochemical techniques confirm multiple Pt loadings have been achieved via the galvanic replacement process. The boost in ORR activity for the PtCu catalyst was determined to be a result of its lower affinity towards (site-blocking) OH adsorption. A unique catalyst degradation study explains the mechanism of initial catalyst ORR deactivation for both monometallic and bimetallic Pt-based catalysts. Finally, a rigorous and pioneering examination of how Pt surface passivation affects ORR dynamics is presented.
Book Synopsis Rational Design of Transition Metal-Nitrogen-Carbon Electrocatalysts for Oxygen Reduction Reaction by : Zhuang Liu
Download or read book Rational Design of Transition Metal-Nitrogen-Carbon Electrocatalysts for Oxygen Reduction Reaction written by Zhuang Liu and published by . This book was released on 2018 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT OF THE DISSERTATION Rational Design of Transition Metal-Nitrogen-Carbon Electrocatalysts for Oxygen Reduction Reaction by Zhuang Liu Doctor of Philosophy in Chemical Engineering University of California, Los Angeles, 2018 Professor Yunfeng Lu, Chair The harvest and conversion of energy is of crucial importance for human civilization. Today, the fast growth in energy consumption, together with the environmental problems caused by fossil fuel usage, calls for renewable and clean energy supply, such as solar, wind, geothermal, and tidal energy. However, such energies are not consistent in both time and location, bringing energy storage on request. Intensive research has been focused on the development of electrochemical energy storage (EES) devices. Among these EES devices, hydrogen fuel cells and metal-air batteries have attracted the special attention because of their high theoretical energy densities. Yet, one major issue lies in the sluggish oxygen reduction reaction (ORR) that takes place at the cathodes. For example, the theoretical voltage of a hydrogen-oxygen fuel cell is 1.23 V (standard condition). However, the voltage output obtained under a meaningful current density is only about 0.7 V, where the voltage loss is primarily caused by the overpotential in the cathodes. Developing efficient electro-catalysts, which can lower the overpotential of ORR, is indispensable for achieving high performance devices. The state-of-the-art ORR electro-catalysts are generally based on platinum, which is limited by cost and scarcity. Developing electro-catalysts based on earth abundant metal elements is critical for large-scale application of fuel cells and metal-air batteries. Among the non-precious-metal catalysts (NPMCs) explored in recent decades, pyrolyzed iron-nitrogen-carbon (Fe-N-C) catalysts is widely regarded as the most promising candidate for replacing platinum due to their high activity. However, the traditional method for preparing Fe-N-C catalysts involves high-temperature pyrolysis of the precursors, which is a highly complex and unpredictable process. As-prepared Fe-N-C catalysts usually contain mixed chemical phases (e.g., Fe-based nanoparticles, Fe-N coordination site and various nitrogen species), as well as carbon scaffolds with random morphology. Such complexity makes it difficult to identify the active site and control the porous structure. Though progress has been made in improving their performance through delicate selection of precursors, such process is largely based on test-and-trial method, shedding little light on the understanding of the material. In this dissertation, we designed a novel "post iron decoration" synthetic strategy towards efficient Fe-N-C catalysts, which de-convolutes the growth of iron and nitrogen species, enables the rational design of the catalyst structure, and provides a series of effective model materials for active site probing. Specifically, liquid iron penta-carbonyl was used to wet the surface of mesoporous N-doped carbon spheres (NMC), whose porous structure is determined by the template used for preparation. The obtained Fe(CO)5/NMC complex was then pyrolyzed to generate the Fe/NMC catalysts. Through comparative study and thorough material characterization, we demonstrated that the pyridinic-N of NMC anchors the Fe atoms to form Fe-Nx active sites during pyrolysis, while the graphitic-N remains ORR active. The excessive Fe atoms were aggregated forming fine nanoparticles, which were subsequently oxidized forming amorphous-iron oxide/iron crystal core-shell structure. All the composing elements of Fe/NMC catalysts are uniformly distributed on the NMC scaffold, whose porous structure is shown to be not affected by Fe decoration, guaranteeing the effective exposure of active sites. The best performing Fe/NMC catalysts exhibited a high half-wave potential of 0.862 V, which is close to that of the benchmark 40% Pt/C catalyst. Such high activity is primarily attributed to the Fe-Nx active sites in the catalysts. While the surface oxidized Fe crystallites though not being the major active site, is revealed to catalyze the reduction of HO2-, the 2e ORR product, facilitating the 4e reduction of oxygen. Finally, such synthetic strategy is successfully extended to prepare other Me-N-C materials. Based on the established understanding of the active sites, we then complexed the active Fe(CO)5 molecules with a N-rich metal-organic framework (ZIF-8) to form a precursor, which was subsequently pyrolyzed to form Fe-NC catalysts. During the pyrolysis, Fe(CO)5 reacts homogeneously with the ZIF-8 scaffold, leading to the formation of uniform distribution of Fe-related active sites on the N-rich porous carbon derived from ZIF-8. The zinc atoms in the crystalline structure of ZIF-8 serves as thermo-sacrificial template, resulting in the formation of hierarchical pores that provide abundant easily accessible ORR active sites. In virtue of these advantageous features, the best performing Fe-NC catalyst exhibited a high half-wave potential of 0.91 V in rotating disk electrode experiment in 0.1 M NaOH. Furthermore, zinc-air battery constructed with Fe-NC-900-M as the cathode catalyst exhibited high open-circuit voltage (1.5 V) and a peak power density of 271 mW cm-2, which outperforms those made with 40% Pt/C catalyst (1.48 V, 1.19 V and 242 mW cm-2), and most noble-metal free ORR catalysts reported so far. Finally, such a synthetic method is economic and easily-scalable, offering possibility for further activity and durability improvement.
Book Synopsis Advanced Electrocatalysts for Low-Temperature Fuel Cells by : Francisco Javier Rodríguez-Varela
Download or read book Advanced Electrocatalysts for Low-Temperature Fuel Cells written by Francisco Javier Rodríguez-Varela and published by Springer. This book was released on 2018-10-09 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the reader to the state of the art in nanostructured anode and cathode electrocatalysts for low-temperature acid and alkaline fuel cells. It explores the electrocatalysis of anode (oxidation of organic molecules) and cathode (oxygen reduction) reactions. It also offers insights into metal-carbon interactions, correlating them with the catalytic activity of the electrochemical reactions. The book explores the electrocatalytic behaviour of materials based on noble metals and their alloys, as well as metal-metal oxides and metal-free nanostructures. It also discusses the surface and structural modification of carbon supports to enhance the catalytic activity of electrocatalysts for fuel-cell reactions.
Book Synopsis Fundamental Understanding and Atomic-Scale Design of Novel Catalysts for Efficient Electrochemical Reactions by : Qiaowan Chang
Download or read book Fundamental Understanding and Atomic-Scale Design of Novel Catalysts for Efficient Electrochemical Reactions written by Qiaowan Chang and published by . This book was released on 2021 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: The availability of renewable energy sources (solar and wind) provides opportunities to replace many traditional chemical reactions by the electrochemical processes to achieve industrial upgrading, including direct ethanol fuel cells (DEFCs), hydrogen peroxide (H2O2) production, and carbon dioxide (CO2) conversion. However, the rates of many important reactions involved in electrochemical processes are too slow and the selectivity of targeted products also needs to be improved. The key to solve these challenges is to design better electrocatalysts. In this thesis, some strategies to design advanced electrocatalysts are investigated. The first strategy is to control the morphology and surface composition of the Platinum (Pt) nanocube-based electrocatalyst in DEFCs to selectively cleave the C-C bond in ethanol to improve its energy utilization. The (100)-exposed Pt38Ir nanocubes with one-atom-thick Ir-rich skin exhibited unprecedented EOR activity, high CO2 selectivity and long-term stability, due to the promotion of C-C bond cleavage and CO desorption from the catalyst surface. Furthermore, we show that the complete oxidization of ethanol to CO2 was achieved by the Rh single atom on the Pt(100) surface, demonstrating the great potential of the decoration of single atom catalysts on the metallic surface in electrochemical reactions. The second example is to tune the local chemical coordination between atomic catalyst clusters (metal) and their support materials (defect carbons) using a composite approach to achieve the synergistic effect in H2O2 electrochemical production. A catalyst composed of oxidized carbon nanotubes and clusters of three to four partially oxidized palladium (Pd) atoms was prepared, forming a special coordination (Pd-O-C) between carbon material and partially oxidized Pd atoms. This coordination can significantly enhance its H2O2 production rate with > 90% selectivity and shorten the production time. The third strategy is to control the intermediate state of catalyst to promote CO2 reduction. In previous studies, Pd was found to transform into palladium hydride (PdH) during the reaction and the latter was believed to be beneficial for syngas production. Based on this finding, the electrocatalyst was directly designed to partially hydridize Pd nanocubes. In comparison with pure metallic Pd, partial hydridization of Pd structure (PdH0.40) showed an earlier transformation to the key intermediate, leading to enhanced syngas production. As a result, the suitable operation potential range can be extended, resulting in a more flexible working condition for potential industrial applications. Overall, the above three strategies for designing electrocatalysts are explored in this thesis work. The results will provide fundamental understanding and guidance for rational design of highly efficient electrocatalysts for crucial electrochemical reactions, getting one step closer to the industrial applications related to sustainable and green chemical engineering.
Book Synopsis Electrocatalysis in Fuel Cells by : Minhua Shao
Download or read book Electrocatalysis in Fuel Cells written by Minhua Shao and published by MDPI. This book was released on 2018-09-28 with total page 689 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Electrocatalysis in Fuel Cells" that was published in Catalysts
Book Synopsis Computational Electrochemistry by : S. Paddison
Download or read book Computational Electrochemistry written by S. Paddison and published by The Electrochemical Society. This book was released on 2015-12-28 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis PEM Fuel Cell Electrocatalysts and Catalyst Layers by : Jiujun Zhang
Download or read book PEM Fuel Cell Electrocatalysts and Catalyst Layers written by Jiujun Zhang and published by Springer Science & Business Media. This book was released on 2008-08-26 with total page 1147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proton exchange membrane (PEM) fuel cells are promising clean energy converting devices with high efficiency and low to zero emissions. Such power sources can be used in transportation, stationary, portable and micro power applications. The key components of these fuel cells are catalysts and catalyst layers. “PEM Fuel Cell Electrocatalysts and Catalyst Layers” provides a comprehensive, in-depth survey of the field, presented by internationally renowned fuel cell scientists. The opening chapters introduce the fundamentals of electrochemical theory and fuel cell catalysis. Later chapters investigate the synthesis, characterization, and activity validation of PEM fuel cell catalysts. Further chapters describe in detail the integration of the electrocatalyst/catalyst layers into the fuel cell, and their performance validation. Researchers and engineers in the fuel cell industry will find this book a valuable resource, as will students of electrochemical engineering and catalyst synthesis.
Book Synopsis Durable Pt-based Catalysts for Oxygen Reduction Reaction in Fuel Cell by : Zeyan Liu
Download or read book Durable Pt-based Catalysts for Oxygen Reduction Reaction in Fuel Cell written by Zeyan Liu and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fuel cells are devices that can efficiently convert fuels into electricity without the limitation of the Carnot cycle. Particularly, hydrogen fuel cells have attracted enormous interest due to their high energy density, high efficiency, and low environmental impacts. The most widely adopted proton-exchange-membrane fuel cells (PEMFCs) use platinum (Pt) catalysts to drive both anode and cathode reactions. To date, the most significant roadblock to the broad dissemination of this green energy technology remains the acceleration and retention of the reaction rate of oxygen reduction reaction (ORR) at the cathode. Developing robust, active, and cost-effective ORR catalysts is the solution to this challenge.In my first work, I demonstrated a Cu doping strategy to enhance the intrinsic activity and durability of octahedral PtNi nanoparticles in the rotating-disk-electrode (RDE) setting. By a novel integration of simulations and growth tracking experiments, we uncover the beneficial role of increased surface Pt composition, which reduces the generation of surface vacancies and subsequent dissolution of sub-surface Cu and Ni atoms. Unlike the well-controlled RDE system, the critical role of mass transports in a practical membrane-electrode-assembly (MEA) system demands additional consideration in stability-enhancing strategies. Therefore, in my subsequent work, I recognized the critical challenge in MEA with ultralow Pt loading and designed a graphene-nanopocket-encaged platinum cobalt nanocatalyst with good electrochemical accessibility and exceptional durability in practical MEA testing. With the greatly improved rated power and durability, a 6.8 gram Pt loading is projected for a 90-kW PEMFC light-duty vehicle, approaching that used in a typical catalytic converter. Furthermore, I presented a unique design of ultrafine Pt nanocatalysts with embedded cobalt oxide clusters, which further improve the catalyst stability for durable PEMFCs. This endohedral-oxide design exploits the strong Pt/oxide interaction, which grants the catalyst its exceptional structural and chemical durability, without sacrificing activity. The developed nanocatalyst exhibits exceptional durability promising an outstanding projected lifetime of 15,000 hours.
Book Synopsis Design and in Situ Characterization of Novel Nanostructured Materials for Fuel Cells by : Yin Xiong
Download or read book Design and in Situ Characterization of Novel Nanostructured Materials for Fuel Cells written by Yin Xiong and published by . This book was released on 2019 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis The Rational Design of Selective Electrocatalysts for Renewable Energy Devices by : Daniel F. Abbott
Download or read book The Rational Design of Selective Electrocatalysts for Renewable Energy Devices written by Daniel F. Abbott and published by . This book was released on 2015 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rational design of electrocatalysts is paramount to the development of electrochemical devices. In particular, modifications to the structure and electronic properties of a particular catalyst can have a strong influence on the activity and selectivity towards various electrochemical reactions or pathways. In many cases this can lead to a particular reaction pathway being opened or closed, the formation of intermediates being stabilized or inhibited, the adsorption of poisonous species being mitigated, or the removal of poisonous species being promoted. In the this dissertation the design and characterization of catalysts for electrochemical devices (fuel cells, electrolyzers, and hydrogen pumps) will be discussed with regards to tailoring the selectivity in order to promote or inhibit certain electrochemical reactions. The electrochemical reactions of primary interest will include the methanol oxidation reaction (MOR), the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen oxidation reaction (HOR).
Book Synopsis Nanoscale Design and Engineering of Electro-catalysts in Fuel Cell and Water Electrolyzer Energy Conversion by : Weichuan Xu
Download or read book Nanoscale Design and Engineering of Electro-catalysts in Fuel Cell and Water Electrolyzer Energy Conversion written by Weichuan Xu and published by . This book was released on 2018 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrocatalysis as an emerging clean energy strategy provides promising future application compared to conventional power solutions. However, the barriers to wide adoption remain challenging, such as catalyst price, storage weight, durability in extreme environment, fuel safety issues and its availability to the public. Recent advances in nanomaterial and nanotechnology enables rational design and synthesis of new catalysts with enhanced performance for heterogeneous electrocatalysis. Herein we propose the Nanoscale Design and Engineering of Electro-catalysts in Fuel Cell and Water Electrolyzer Energy Conversion. This dissertation provides some successful examples of electrode catalyst design and fabrication for boosting electrocatalysis in fuel cell and electrolyzer. Special emphasis is put on theories, synthesis strategies, performance boost to achieve the goal of enhancing catalyst activity whiling reducing materials cost; identifying durability issues and giving solutions; realizing low total over potential in bifunctional electrocatalysis and predicting catalyst performance from simulation to find out ideal composition. The engineered nanomaterials in this dissertation mainly take advantages of (1) optimization of nanoparticle size by novel support (Nb doped TiO2) or synthesis method (polymer-assisted chemical solution) to increase electrochemical active surface area for enhanced charge transfer and catalysis activity (Chapter 2, 3, and 4), (2) synergistic effect from support material (TiO2 for Pd, carbon materials for perovskite oxide) to improve nanoparticle deposition and exposure during reactions (Chapter 2, 3, and 4), (3) tunable electronic structure (A-site deficiency, A-site excess, and partially substitution of B-site transition metal cations) on cost-effective perovskite catalyst to replace noble metal (Pt, IrO2) for bifunctional oxygen electrocatalysis in unitized fuel cells (Chapter 3 and 4), and (4) activity description from atomic level to understand electrocatalysis mechanism and make prediction for new catalysts (Chapter 4 and 5). Pd on Nb-TiO2-C supports has increased reaction intensity, selectivity without sacrifice of durability. A-site nonstoichiometry and B-site doping successfully enhances oxygen bifunctionality of cost-effective perovskite catalysts; First-principle study suggests new Pd-Cu composition to achieve a balance between reaction activity and expense.
Book Synopsis Nanotechnology in Electrocatalysis for Energy by : Alessandro Lavacchi
Download or read book Nanotechnology in Electrocatalysis for Energy written by Alessandro Lavacchi and published by Springer Science & Business Media. This book was released on 2014-01-28 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on nanotechnology in electrocatalysis for energy applications. In particular the book covers nanostructured electrocatalysts for low temperature fuel cells, low temperature electrolyzers and electrochemical valorization. The function of this book is to provide an introduction to basic principles of electrocatalysis, together with a review of the main classes of materials and electrode architectures. This book will illustrate the basic ideas behind material design and provide an introductory sketch of current research focuses. The easy-to-follow three part book focuses on major formulas, concepts and philosophies. This book is ideal for professionals and researchers interested in the field of electrochemistry, renewable energy and electrocatalysis.
Book Synopsis Low Platinum Fuel Cell Technologies by : Junliang Zhang
Download or read book Low Platinum Fuel Cell Technologies written by Junliang Zhang and published by Springer. This book was released on 2020-11-21 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces readers to the fundamental physics and chemistry of the proton exchange membrane fuel cell (PEMFC), followed by discussions on recent advances in low platinum electrocatalysis and related catalyst development for PEMFC (the book’s primary focus), methods of membrane electrode assembly (MEA) fabrication for low platinum catalysts, and durability issues in connection with MEA. While energy and environmental issues are becoming the two main subjects in global sustainable development, the proton exchange membrane fuel cell (PEMFC), a clean and efficient new energy technology, has attracted more and more attention in recent years The major hurdle for more extensive applications of the PEMFC, especially for the automotive sector, is the high platinum loading requirement. Readers will gain a comprehensive understanding of the fundamentals and methods of low platinum PEMFC. This book is intended for researchers, engineers and graduate students in the fields of new energy technology, the fuel cell vehicle industry and fuel cell design.
