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1
Gcilitshana, Oko Unathi. "Electrochemical Characterization of Platinum based anode catalysts for Polymer Exchange Membrane Fuel Cell." Thesis, University of the Western Cape, 2008. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5972_1266961431.
Повний текст джерелаАнотація:
In this study, the main objective was to investigate the tolerance of platinum based binary anode catalysts for CO poisoning from 10ppm up to1000ppm and to identify the
best anode catalysts for PEMFCs that tolerates the CO fed with reformed hydrogen.
2
Bauer, Alexander Günter. "Direct methanol fuel cell with extended reaction zone anode : PtRu and PtRuMo supported on fibrous carbon." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/913.
Повний текст джерелаАнотація:
The direct methanol fuel cell (DMFC) is considered to be a promising power source for portable electronic applications and transportation.
At present there are several challenges that need to be addressed before the widespread commercialization of the DMFC technology can be implemented. The methanol electro oxidation reaction is sluggish, mainly due to the strong adsorption of the reaction intermediate carbon monoxide on platinum. Further, methanol crosses over to the cathode, which decreases the fuel utilization and causes cathode catalyst poisoning. Another issue is the accumulation of the reaction product CO₂ (g) in the anode, which increases the Ohmic resistance and blocks reactant mass transfer pathways.
A novel anode configuration is proposed to address the aforementioned challenges. An extended reaction zone (thickness = ∼100-300 µm) is designed to facilitate the oxidation of methanol on sites that are not close to the membrane-electrode interface. Thus, the fuel concentration near the membrane may decrease significantly, which may mitigate adverse effects caused by methanol cross-over. The structure of the fibrous electrode, with its high void space, is believed to aid the disengagement of CO₂ gas.
In this thesis the first objective was to deposit dispersed nanoparticle PtRu(Mo) catalysts onto graphite felt substrates by surfactant mediated electrodeposition. Experiments, in which the surfactant concentration, current density, time and temperature were varied, were conducted with the objective of increasing the active surface area and thus improving the reactivity of the electrodes with respect to methanol electro-oxidation. The three-dimensional electrodes were characterized with respect to their deposit morphology, surface area, composition and catalytic activity.
The second objective of this work was to utilize the catalyzed electrodes as anodes for direct methanol fuel cell operation. The fuel cell performance was studied as a function of methanol concentration, flow rate and temperature by using a single cell with a geometric area of 5 cm².
Increased power densities were obtained with an in-house prepared 3D PtRu anode compared to a conventional PtRu catalyst coated membrane.
Coating graphite felt substrates with catalytically active nanoparticles and the utilization of these materials, is a new approach to improve the performance of direct fuel cells.
3
Білоус, Тетяна Андріївна, та Геннадій Георгійович Тульський. "Вибір промоторів для електрохімічного синтезу пероксиоцтової кислоти". Thesis, Львівський національний університет ім. Івана Франка, 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/37586.
Повний текст джерелаАнотація:
A high-purity peroxyacetic acid may be produced by electrochemical method. The necessity of using peroxo group promoters is justified. The effect of the additions of CNS⁻, I⁻, Cl⁻, Br⁻ ions on the kinetics of anodic processes in an aqueous 3 mol/dm³ acetic acid solution with sulfuric acid addition have been investigated by the voltammetry method on a platinum electrode. The addition of CNS⁻, I⁻, Cl⁻, Br⁻ ions to the electrolyte composition leads to inhibition of the combined anodic oxygen evolution process. Additions of I⁻, Cl⁻, Br⁻ ions to the electrolyte for electrochemical synthesis of peroxyacetic acid are expedient to use, they contribute to achieving the maximum current efficiency of the final product (1,2 ... 1,5 %). The concentration of additions of ions I⁻, Cl⁻, Br⁻ should not exceed 0,001 mol/dm³. Electrochemical synthesis of peroxyacetic acid is advisable to conduct in the range of current densities of 500…1500 A/m², at which the maximum current efficiency of the target product is observed.
4
Rismanchian, Azadeh. "Copper Nickel Anode for Methane SOFC." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1312299949.
Повний текст джерела
5
ANTONIASSI, RODOLFO M. "Desempenho elétrico e distribuição dos produtos da célula a combustível com etanol direto utilizando Pt/C, PtSn/C(liga) e PtSnO2/C como eletrocatalisadores anódicos." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10515.
Повний текст джерелаАнотація:
Made available in DSpace on 2014-10-09T12:41:23Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:03:56Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
6
Drillet, Jean-François. "Einsatz von Poly(3,4-ethylendioxithiophen) als Katalysatorträger und Methanolbarriere in der Anode der Direktmethanol-Brennstoffzelle." Aachen Shaker, 2008. http://d-nb.info/992916550/04.
Повний текст джерела
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SILVA, DIONISIO F. da. "Preparacao de eletrocatalisadores PtRu/C e PtSn/C utilizando feixe de eletrons para aplicacao como anodo na oxidacao direta de metanol e etanol em celulas a combustivel de baixa temperatura." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9475.
Повний текст джерелаАнотація:
Made available in DSpace on 2014-10-09T12:27:08Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T13:56:45Z (GMT). No. of bitstreams: 0
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
8
Cesetti, Lorenzo. "Systematic study of in-situ sodium plating/stripping on anode free substrates for sodium ion batteries." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
Знайти повний текст джерелаАнотація:
Gli oggetti di studio di questo lavoro di tesi sono le batterie agli ioni-sodio, in particolare una loro variante ancora in fase di sviluppo denominata “anode-free”.
Seppur questi accumulatori al sodio non siano nuovi ma conosciuti da tempo, è solamente dal 2010 che gli studi al riguardo si sono intensificati, tanto da portare alla realizzazione di diversi prototipi in pochi anni.
Le maggiori difficoltà nel loro sviluppo sono state riscontrate nella scelta del materiale costituente l’anodo.
Per ovviare al problema sono state ideate le batterie agli ioni-sodio “anode-free”: l’anodo è rappresentato da un semplice collettore di corrente, generalmente alluminio o rame, dove gli ioni-sodio si depositano, riducendosi e formando sodio metallico in situ durante la carica; al contrario, durante la scarica, è il sodio metallico che si ossida tornando ione e migrando verso il catodo.
Il lavoro di tesi ivi proposto è stato sviluppato presso l’Energy Storage Group del College of Engineering della Swansea University di Swansea (UK).
Sono stati esaminati tre substrati differenti valutando l’idoneità di ciascuno di essi ad un’applicazione come anodo in un accumulatore agli ioni-sodio “anode-free”, attraverso tecniche di caratterizzazione standard quali Galvanostatic Cycling (GC), Cyclic Voltammetry (CV) ed analisi al microscopio.
I materiali presi in esame sono stati: acciaio inossidabile, acciaio inossidabile rivestito di nichel ed un substrato di nichel chiamato nichel foam.
Dopo aver visto che l’acciaio inossidabile è il substrato in grado di garantire prestazioni migliori, lo step successivo è stato quello di realizzare una vera e propria batteria agli ioni-sodio “anode-free” utilizzando un catodo composto da pirite presodiata.
Le performance della batteria proposta in questa tesi sono state infine confrontate con quelle di un modello di riferimento che impiega un collettore di corrente in alluminio rivestito da carbon black come anodo.
9
Lu, Lanying. "Studies of anode supported solid oxide fuel cells (SOFCs) based on La- and Ca-Doped SrTiO₃." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7068.
Повний текст джерелаАнотація:
Solid oxide fuel cells (SOFCs) have attracted much interest as the most efficient electrochemical device to directly convert chemical energy to usable electrical energy. The porous Ni-YSZ anode known as the state-of-the-art cermet anode material is found to show serious degradation when using hydrocarbon as fuel due to carbon deposition, sulphur poisoning, and nickel sintering. In order to overcome these problems, doped strontium titanate has been investigated as a potential anode material due to its high electronic conductivity and stability in reducing atmosphere. In this work, A-site deficient strontium titanate co-doped with lanthanum and calcium, La₀.₂Sr₀.₂₅Ca₀.₄₅TiO₃ (LSCT[sub](A-)), was examined. Flat multilayer ceramics have been produced using the aqueous tape casting technique by controlling the sintering behaviour of LSCT[sub](A-), resulting in a 450µm thick porous LSCT[sub](A-) scaffold with a well adhered 40µm dense YSZ electrolyte. Impregnation of CeO₂ and Ni results in a maximum power density of 0.96Wcm⁻² at 800°C, higher than those of without impregnation (0.124Wcm⁻²) and with impregnation of Ni alone (0.37Wcm⁻²). The addition of catalysts into LSCT[sub](A-) anode significantly reduces the polarization resistance of the cells, suggesting an insufficient electrocatalytic activity of the LSCT[sub](A-) backbone for hydrogen oxidation, but LSCT[sub](A-) can provide the electronic conductivity required for anode. Later, the cells with the configuration of LSCT[sub](A-)/YSZ/LSCF-YSZ were prepared by the organic tape casting and impregnation techniques with only 300-m thick anode as support. The effects of metallic catalysts in the anode supports on the initial performance and stability in humidified hydrogen were discussed. The nickel and iron impregnated LSCT[sub](A-) cell exhibits a maximum powder density of 272mW/cm² at 700°C, much larger than 43mW/cm² for the cell without impregnation and 112mW/cm² for the cell with nickel impregnation. Simultaneously, the bimetal Ni-Fe impregnates have significantly reduced the degradation rates in humidified hydrogen (3% H₂O) at 700°C. The enhancement from impregnation of the bi-metal can possibly be the result of the presence of ionic conducting Wustite Fe₁₋ₓO that resides underneath the Ni-Fe metallic particles and better microstructure. Third, in order to improve the ionic conductivity of the anode support and increase the effective TPBs, ionic conducting ceria was impregnated into the LSCT[sub](A-) anode, along with the metallic catalysts. The CeO₂-LSCT[sub](A-) cell shows a poor performance upon operation in hydrogen atmosphere containing 3% H₂O; and with addition of metallic catalysts, the cell performance increases drastically by almost three-fold. However, the infiltrated Ni particles on the top of ceria layer cause the deposition of carbon filament leading to cell cracking when exposure to humidified methane (3% H₂O). No such behaviour was observed on the CeO₂-NiFe impregnated anode. The microstructure images of the impregnated anodes at different times during stability testing demonstrate that the grain growth of catalysts, the interaction between the anode backbone and infiltrates, and the spalling of the agglomerated catalysts are the main reasons for the performance degradation. Fourth, the YSZ-LSCT[sub](A-) composites including the YSZ contents of 5-80wt.% were investigated to determine the percolation threshold concentration of YSZ to achieve electronic and ionic conducting pathways when using the composite as SOFC anode backbone. The microstructure and dilatometric curves show that when the YSZ content is below 30%, the milled sample has a lower shrinkage than the unmilled one due to the blocking effect from the well distributed YSZ grains within LSCT[sub](A-) bulk. However, at the YSZ above 30% where two phases start to form the individual and interconnected bulk, the composites without ball milling process show a lower densification. The impact of YSZ concentration and ball milling process on the electrical properties of the composites reveals that the percolation threshold concentration is not only dependant on the actual concentration, but also related to the local arrangement of two phases. In Napier University, the electroless nickel-ceramic co-depositon process was investigated as a manufacturing technique for the anodes of planar SOFCs, which entails reduced costs and reduced high-temperature induced defects, compared with conventional fabrication techniques. The Ni-YSZ anodes prepared by the electroless co-deposition technique without the addition of surfactant adhere well to the YSZ electrolyte before and after testing at 800°C in humidified hydrogen. Ni-YSZ anodes co-deposited with pore-forming starch showed twice the maximum power density compared with those without the starch. It has therefore been demonstrated that a porous Ni-YSZ cermet structure was successfully manufactured by means of an electroless plating technique incorporating pore formers followed by firing at 450°C in air. Although the use of surfactant (CTAB) increases the plating thickness, it induces the formation of a Ni-rich layer on the electrolyte/anode interface, leading to the delamination of anode most likely due to the mismatched TECs with the adjacent YSZ electrolyte.
10
Chien, Chang-Yin. "Methane and Solid Carbon Based Solid Oxide Fuel Cells." University of Akron / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=akron1299670407.
Повний текст джерела
11
Zier, Martin. "Untersuchungen zum Einfluss von Elektrodenkennwerten auf die Performance kommerzieller graphitischer Anoden in Lithium-Ionen-Batterien." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-156682.
Повний текст джерелаАнотація:
Die vorliegende Arbeit liefert einen Beitrag zum Verständnis der elektrochemischen Prozesse an der Elektrodengrenzfläche und im Festkörper graphitischer Anoden für Lithium-Ionen-Batterien. Der Zusammenhang zwischen den intrinsischen Eigenschaften des Aktivmaterials und den resultierenden Eigenschaften von Kompositelektroden stand dabei im Fokus der Untersuchungen. Die Temperaturabhängigkeit von Materialeigenschaften (Diffusionskoeffizient, Austauschstromdichte) und Elektrodeneigenschaften (Verhalten unter Strombelastung) wurde in einem Bereich von 40 °C bis -10 °C erfasst. Dazu werden elektrochemische Charakterisierungsmethoden aus der Literatur vorgestellt und hinsichtlich ihrer Gültigkeit für die Anwendung an realen Elektroden evaluiert. Die elektrochemisch aktive Oberfläche wurde bestimmt und stellte sich als ausschlaggebender Parameter für die Bewertung der Elektrodenprozesse heraus. Auf Basis korrigierter Elektrodenoberflächen konnten Austauschstromdichten für die konkurrierenden Prozesse Lithium-Interkalation und -Abscheidung ermittelt werden. Zusammen mit Kennwerten zur Keimbildungsüberspannung für Lithium-Abscheidung flossen die ermittelten Kennwerte in eine theoretische Berechnung des Zellstroms ein. Es konnte gezeigt werden, dass die Lithium-Abscheidung kinetisch deutlich gegenüber der Lithium-Interkalation bevorzugt ist, nicht nur bei niedriger Temperatur. Die Übertragbarkeit wissenschaftlicher Grundlagenexperimente auf kommerzielle Systeme war bei allen Versuchen Gegenstand der Untersuchungen. In einem separaten Beispiel einer Oberflächenmodifikation mit Zinn wurde diese Problematik besonders verdeutlicht. Zusätzlich wurde die parasitäre Abscheidung von Lithium auf graphitischen Anoden hinsichtlich der Nachweisbarkeit und Quantifizierung evaluiert. Hierfür wurde eine neue Untersuchungsmethode im Bereich der Lithium-Ionen-Batterie zur besseren Detektion von Lithium-Abscheidung und Grenzflächen-Morphologie mittels Elektronenmikroskopie entwickelt. Die Osmiumtetroxid (OsO4) Färbung ermöglichte eine deutliche Verbesserung des Materialkontrasts und erlaubte somit eine gezielte Untersuchung von graphitischen Anoden nach erfolgter Lithium-Abscheidung. Darüber hinaus konnte die selektive Reaktion des OsO4 für eine genauere Betrachtung der Solid Electrolyte Interphase genutzt werden. Eine Stabilisierung der Proben an Luft und im Elektronenstrahl konnte erreicht werdenThis work sheds light on the electrochemical processes occurring at commercially processed graphitic anodes. It raises the question whether values published in literature for mostly ideal electrode systems can be readily taken for simulation and design of real electrodes in high-energy cells. A multiple step approach is given, evaluating different methods to determine electrode and material properties independently. The electrochemically active surface area was shown to be a crucial parameter for the calculation of electrode kinetics. Using exchange current densities corrected for the electrode surface area, the overall charging current in a cell could be calculated. The resulting part of lithium deposition in the charging process is strikingly high, not only at low temperatures. To further investigate lithium deposition in terms of morphology and quantity, a method was developed for graphitic anodes. Osmium tetroxide (OsO4) staining serves well as a tool to strongly increase material contrast in electron microscopy. Thus lithium dendrites could be made visible in an unprecedented manner. Furthermore, the selective chemical reaction of osmium tetroxide allows for a better investigation of the multi-layer solid electrolyte interphase as was shown in transmission electron microscopy. Using the staining method, a stabilization of the sample under air and in the electron beam could be achieved
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ANTONIASSI, RODOLFO M. "Preparação de nanopartículas de platina com diferentes morfologias nos materiais Pt/C e PtSnO2/C para aplicação como ânodo em células a combústível de etanol direto." reponame:Repositório Institucional do IPEN, 2017. http://repositorio.ipen.br:8080/xmlui/handle/123456789/28036.
Повний текст джерелаАнотація:
Submitted by Pedro Silva Filho (pfsilva@ipen.br) on 2017-11-22T16:42:40Z
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Neste trabalho foi estudado o efeito da adição de íons haletos (Cl-, Br- e I-) sobre a morfologia das nanopartículas de Pt na produção de catalisadores de Pt/C e PtSnO2/C. Foi desenvolvida uma metodologia de síntese simples capaz de produzir nanopartículas de Pt predominantemente cúbicas com orientação preferencial Pt(100), diretamente suportadas em carbono sem o uso de agentes estabilizantes. Brometo de potássio foi utilizado como agente direcionador de superfície para obtenção do material preferencialmente orientado. O controle de adição do precursor de Pt e de KBr foi crucial para obter nanocubos de Pt de 8 nm bem dispersos sobre o suporte. Na preparação dos catalisadores de PtSnO2/C, o processo de adição do SnCl2 também foi decisivo na obtenção das nanopartículas de Pt com tamanho e morfologia de interesse. Nanocubos de Pt coexistindo com SnO2 disperso foram exclusivamente obtidos ao adicionar o SnCl2 na etapa final da síntese, quando as nanopartículas cúbicas de Pt já estavam formadas. Enriquecidos de domínios Pt(100), os materiais em forma cúbica de Pt/C e PtSnO2/C se mostraram menos afetados pelo acúmulo dos intermediários indesejados provenientes da reação de eletro-oxidação de etanol e foram mais tolerantes ao envenenamento por monóxido de carbono. Resultados similares foram observados para a oxidação de CO e metanol, utilizados como apoio para compreensão da eletro-oxidação de etanol. O efeito morfológico destes materiais no desempenho elétrico em célula a combustível de etanol direto foi avaliado. Pt/C e PtSnO2/C contendo nanopartículas de Pt com orientação preferencial Pt(100) forneceram maiores valores de densidade de potência e de seletividade para CO2 comparados aos catalisadores de Pt/C e PtSnO2/C com nanopartículas de Pt sem orientação preferencial.
Tese (Doutorado em Tecnologia Nuclear)
IPEN/T
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
13
Mougenot, Mathieu. "Elaboration et optimisation d'électrodes de piles PEMFC à très faible taux de platine par pulvérisation plasma." Phd thesis, Université d'Orléans, 2011. http://tel.archives-ouvertes.fr/tel-00667739.
Повний текст джерелаАнотація:
Cette thèse réalisée dans le cadre des projets PIE CNRS AMELI-0Pt et AMEPlas et ANR AMADEUS a regroupé plusieurs entités autour de la thématique des piles à combustible : Dreux Agglomération puis l'Agence Innovation Made In Dreux (MID), le GREMI, le LACCO et initialement l'industriel MHS Equipment. L'objectif de ce travail est l'élaboration par voie plasma et l'optimisation d'électrodes de piles à combustible de type PEMFC et SAMFC dans le but d'obtenir de bonnes performances avec des charges de platine ultra faibles ou sans platine. Le projet a été organisé en quatre étapes : l'étude de la croissance simultanée de platine et de carbone co-pulvérisés par plasma, la dispersion optimale de quantités ultra faibles de catalyseur, le remplacement du platine par un alliage bimétallique à base de palladium, et le dépôt direct du catalyseur sur la membrane par plasma. En utilisant un faisceau synchrotron de rayons X (Synchrotron SOLEIL), en collaboration avec le CRMD, l'étude GISAXS des couches minces Pt-C co-pulvérisés a révélé l'organisation particulière du platine dans ce type de nanostructure. Ces couches minces Pt-C offrent d'excellentes performances (20 kW.gPt-1) avec des charges de platine ultra faibles. Des électrodes PdPt (5 %at Pt) faiblement chargées permettent d'atteindre de bonnes performances en PEMFC quasiment sans platine (12,5 kW.gPd-1 et 250 kW.gPt-1). L'étude de l'activité de catalyseurs PdAu vis-à-vis de l'oxydation du glycérol a révélé l'origine des effets synergiques du palladium et de l'or en milieu alcalin. Le dépôt plasma direct de platine associé ou non au dépôt de carbone sur membrane a été optimisé. Les performances obtenues avec des CCM (Catalyst Coated Membrane) plasma démontrent l'intérêt de ce type d'architecture.
14
Jie-YuYang and 楊捷宇. "Recovery of Palladium, Platinum and Rhodium from Copper Anode Slime." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/xxhk4w.
Повний текст джерела
15
Hsiao, Shun-yu, and 蕭舜予. "Using Platinum to Modify Ruthenium Anode Catalyst on Application of DMFC." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/85246766874898848523.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
材料科技研究所
96
The RucorePtshell nanocatalysts were synthesized by two different methods as the anode catalysts for DMFC for improving the electro-catalytic activity toward methanol and lower the consumption of platinum as well. In the first part, Ru seeds are intended to synthesize as nuclei for growth of Pt. The synthesized Ru seeds of ultra-small size was obtained by reduction of Ru(III) ions with ethylene glycol at the condition of high pH value. Subsequently, the Ru seeds were collected and put into another Ru (III) ethylene glycol solution at low pH value as nuclei to ensure no new seeds were formed. Uniform Ru nanoparticles with larger size were obtained by taking original Ru seeds as nuclei. Later RucorePtshell black were synthesized by the displacement reaction between the Pt(II) ions and the synthesized Ru nanoparticles in the Pt(II) ethylene glycol solution. As the results, the Pt (II) ions were firstly reduced by the formed glycolic acid and oxalic acid in the solution. The prefer-oriented growth of Pt in the first 4 hours resulted elongate morphology by TEM analysis. The structure of the formed nanoparticles was identified as RucorePtcluster from XAS spectra. Then the PtcoreRucluster could be obtained by the displacement reaction of Ru with Pt(II) in the next 4 hours. The synthesized PtcoreRucluster possessed the highest electro-catalytic activity toward methanol oxidation, which is resulting from their optimal alloy extent. However, the morphology of elongate would be decomposed into sphere due to the over displacement reaction after 12 hours. On the other hand, nanoparticles with the architecture of Pt shell on Ru-TiO2 core were investigated. Firstly, the core composed of Ru : TiO2 = 3 : 7 was prepared by Modified-Watanabe method, followed by heat treatment for electronic conductive and stable rutile TiO2. The role of TiO2 in Ru-TiO2 core could provide Ru-O-Ti bonding for prevention of Ru from dissolution. However, Ru-TiO2 cores showed only parts of rutile TiO2 accompanied with untransformed anatase after 800 oC treatment at 1 hr. The catalyst with optimal alloy extent and the highest electro-catalytic activity toward methanol oxidation was identified as Ru : TiO2 : Pt = 3 : 7 : 1. With the increase of Pt on the surface of nanoparticles, the degree of CO poisoning and the loss of active sites were found, which lead to poor electrochemical performance.
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Chia-Ming, Chang, and 張家銘. "Modification of Active Carbon Supported Platinum-Ruthenium (PtRu/C) with Cerium Oxide for DMFC Anode Catalysts." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/15971161386648655961.
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Chen, Yan Bo, and 陳彥博. "Review literatures study of catalytic activity of direct ammonia fuel cell anode catalyst by using electrodeposition Zinc modified to Platinum electrode." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/w24k6s.
Повний текст джерелаАнотація:
碩士長庚大學
化工與材料工程學系
105
Direct ammonia fuel cell by using ammonia liquid fed in comparison to hydrogen PEM fuel cell and direct methanol fuel cell, DAFC has higher conversion efficiency than PEMFC, with good theoretical capacity (4750A/kg) and OCV (1.17V). DAFC does not produce carbon-containing compounds. Platinum as anode catalyst is the most effective electro-catalyst towards ammonia oxidation for a direct ammonia fuel cell (DAFC), but there is a poison phenomenon. In the oxidation process nitrogen atoms are not easy to desorb the catalyst surface, resulting in retardation of voltage current density. To enhance the catalytic activity of platinum catalyst and reduce the poison phenomenon, platinum catalyst must be modified with catalyst metals, in enhancing the catalytic performance activity. The use of electrodeposition of zinc metal on platinum metal, may change the surface of the electronic properties and thus affect the surface - molecular interaction.
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Huang, Sheng-Yuan, and 黃聖原. "Multi-Micro Anode Guided Electro-plating System." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/85477721744077729816.
Повний текст джерелаАнотація:
碩士國立中央大學
機械工程研究所
92
Micro Anode Guided Electro-plating System(MAGE) has been used to fabricate a 3-D micrometer scale nickel column in nickel-containing baths.In order to improve the inefficiency of Micro Anode Guided Electro-plating System,we try to research and develop the Multi-Micro Anode Guided Electro-plating System that have much parallel and switching anode in a MAGE.This new system comprises 3 module：Plating mechine,Control system,User's operating system.In this paper,we will give an outline of the Multi-Micro Anode Guided Electro-plating System and make some experiments on Cu-containing baths and Ni-containing baths to analyze the efficiency of Multi-Micro Anode Guided Electro-plating System.
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Wang, Mei-Ling, and 王美齡. "Application of Dimensionally Stable Anode for Via Filling Plating." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/34189191988373736759.
Повний текст джерелаАнотація:
碩士國立中興大學
化學工程學系所
99
In order to solve these problems caused by soluble anodes, Dimensionally Stable Anode (DSA) was examined as a potential alternative. In this thesis, we analyzed different types of DSAs and developed specific plating additives for DSA. The results show that traditional accelerators, such as Sodium 3-Mercapto-1-Propanesulfonate (MPS) and Bis(3-Sulfopropyl) Disulfide (SPS), commonly used in the plating bath with soluble anodes, could not survive for a long time in the plating bath with DSAs. A specially formulated accelerator was able to stay active for a long time in the DSA system. With a compatible accelerator, the DSA was then used to carry out copper filling of through silicon via (TSV). A new copper plating formula was explored and evaluated for this process. Excellent filling performance could be obtained with this formula when employed simultaneously with the new accelerator and DSA in a plating bath. Afterwards, iridium dioxide and two modified DSAs were used to compare with a phosphorus-containing copper anode. Various DSAs and a new accelerator for TSV filling were evaluated and explored using electrochemical analysis instrument, practical plating, and examining cross-sections.
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Deng, Zhen-Hong, and 鄧振宏. "The developing of a anode guided 3D micro electro-plating System." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/61539388270028904784.
Повний текст джерелаАнотація:
碩士國立中央大學
機械工程研究所
93
The main purpose of this thesis is to hope to electro-plating 3D micro-structure (like small components of three-dimensional space , such as little spring , in charge of hollowly ,etc.), and set about studying the feasibility that " 3D micro electro-plating " , develop anode guided 3D micro electro-plating system for this goal. This system use the structure of the module , can subdivide into three major module : Three axles electroplate mechanic-platform , anode guided micro electro-plating module , and control program . After the operation of the system, the user can give electroplate instructions to anode guided 3D micro electro-plating hardware through interface of control program, the anode guided 3D micro electro-plating the system after finishing electroplate instructions or finishing the specific procedure , communication interface of the system will receive electroplate- information and show on control program interface . It is explain and introduced how every module of the system is designed、planned and program is coded . On electroplating-experiment that the anode guided 3D micro electro-plating function is verified and proves server current mode or server voltage mode to electroplating micro-structure , finally , verify the feasibility of " electroplate 3D micro-structure ".
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Zahm, Lance Leon. "Nuclear investigations of the eletrolysis of D₂O using palladium cathodes and platinum anodes." Thesis, 1990. http://hdl.handle.net/1957/37958.
Повний текст джерела
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Chia-ChunWu and 伍家均. "Investigation of Si-based Nanocomposite Anode Materials Utilizing Electroless Nickel Plating for Lithium-ion Batteries." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/qk53au.
Повний текст джерела
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Hsu, Chao-yang, and 許朝陽. "Tin/Graphite Composite Anodes Prepared by Electroless Plating for Lithium-Ion Batteries." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/35590879848957906362.
Повний текст джерелаАнотація:
碩士國立臺南大學
材料科學系碩士班
95
The main developmental aim of lithium-ion cells is light, thin, short, longer battery lifetime, good battery performance and so on. In recent years, as for the development of anode material with high capacity, many researchers focus on the metal modification of graphite or carbon surface in order to enhance the capacity and the cycle life. Therefore, this work is conducted with electroless plating treatment to deposit high active material Sn, on the surface of natural graphite. Scanning electron microscopic morphology (SEM) shows the nano-particle was uniform distribution on the graphite surface. The charge and discharge characteristics, cycle life performance, electrochemical behaviors, and thermal stability are performed by coin cell charge/discharge test, cycle life test, cyclic voltammetry test, and differential scanning calorimetry(DSC) test, respectively. Moreover, to obtain the optimization of various factors for electroless plating treatment, this study inducts L8 of orthogonal array to analyze the cycle life data .The factors of optimization for electroless plating treatment are as follows: the substances of pre-plating bath are 0.15M Sn(BF4)2、0.6M HBF4、2.0M (NH2)2CS, the time of pre-plaing is set for 30 seconds, the [MOH]/[SnCl2] ratio of main plating bath is 12, the hydroxides of main plating bath is KOH, the substances of main plating bath are Sn(0.075M)、 K3C6H5O7 (0.1M), the time of main plating is set for 3 hours, the temperature of main plating is set at 80℃. From this optimum condition, the capacity after 50 cycles is 324 mAh/g, which enhances 109% compared with the one of pristance graphite. Besides, the rate capacity can be maintained 332 mAh/g (95.6%vs.0.1C rate discharge capacity) under 1 C-rate high rate discharge test. DSC scans of lithium intercalated anodes show that Sn-modified on the graphite reduces the thermal stability of the anode.
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Lin, Chun-Chu, and 林俊竹. "Impacts of Sputter-Deposited Platinum Thickness and Molecular Modification of Anodes on Performance of Dye-Sensitized Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/23vu2r.
Повний текст джерелаАнотація:
碩士國立暨南國際大學
應用材料及光電工程學系
102
This study can be divided into two parts. The first part is control over Pt thickness and surface roughness of platinized counter electrode by adjusting sputtering time. A larger surface roughness would be more beneficial to the catalytic activity of Pt. The DSSC using sputtering time of 40 s exhibited the largest short-circuit photocurrent density and highest energy conversion efficiency of 6.81%. Both short-circuit photocurrent density and energy conversion efficiency were reduced as longer sputtering time was employed. So increased Pt thickness was unfavorable for DSSC performance. The sputtering time of 40 s has been regarded as the optimum condition to form the most appropriate Pt thickness of around 30 Å. The second part is molecular modification on TiO2 photoanode by self-assembled monolayers to lower the energy barrier of charge transfer. Seven organic molecules were selected to form self-assembled monolayers in this part. The DSSC modified by AEPA exhibited the largest short-circuit photocurrent density and highest efficiency of 6.67%. Moreover, it has been proved by electrochemical methods that the redox current increased when photoanode was modified by AEPA. Easier and faster charge transport were then resulted, and increased photocurrent and higher efficiency were achieved. The type of terminal group and molecular length also affected surface and interfacial properties of TiO2 electrode, and the photovoltaic parameters and device performance of DSSC were thereby influenced.
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Chen, Te Lung, and 陳德隆. "The Influence of P-doped Cu and Pure Cu Anodes on Microvia Filling by Copper Plating." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/53600066724908960247.
Повний текст джерела
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Zier, Martin. "Untersuchungen zum Einfluss von Elektrodenkennwerten auf die Performance kommerzieller graphitischer Anoden in Lithium-Ionen-Batterien." Doctoral thesis, 2014. https://tud.qucosa.de/id/qucosa%3A27381.
Повний текст джерелаАнотація:
Die vorliegende Arbeit liefert einen Beitrag zum Verständnis der elektrochemischen Prozesse an der Elektrodengrenzfläche und im Festkörper graphitischer Anoden für Lithium-Ionen-Batterien. Der Zusammenhang zwischen den intrinsischen Eigenschaften des Aktivmaterials und den resultierenden Eigenschaften von Kompositelektroden stand dabei im Fokus der Untersuchungen.
Die Temperaturabhängigkeit von Materialeigenschaften (Diffusionskoeffizient, Austauschstromdichte) und Elektrodeneigenschaften (Verhalten unter Strombelastung) wurde in einem Bereich von 40 °C bis -10 °C erfasst. Dazu werden elektrochemische Charakterisierungsmethoden aus der Literatur vorgestellt und hinsichtlich ihrer Gültigkeit für die Anwendung an realen Elektroden evaluiert. Die elektrochemisch aktive Oberfläche wurde bestimmt und stellte sich als ausschlaggebender Parameter für die Bewertung der Elektrodenprozesse heraus.
Auf Basis korrigierter Elektrodenoberflächen konnten Austauschstromdichten für die konkurrierenden Prozesse Lithium-Interkalation und -Abscheidung ermittelt werden. Zusammen mit Kennwerten zur Keimbildungsüberspannung für Lithium-Abscheidung flossen die ermittelten Kennwerte in eine theoretische Berechnung des Zellstroms ein. Es konnte gezeigt werden, dass die Lithium-Abscheidung kinetisch deutlich gegenüber der Lithium-Interkalation bevorzugt ist, nicht nur bei niedriger Temperatur.
Die Übertragbarkeit wissenschaftlicher Grundlagenexperimente auf kommerzielle Systeme war bei allen Versuchen Gegenstand der Untersuchungen. In einem separaten Beispiel einer Oberflächenmodifikation mit Zinn wurde diese Problematik besonders verdeutlicht.
Zusätzlich wurde die parasitäre Abscheidung von Lithium auf graphitischen Anoden hinsichtlich der Nachweisbarkeit und Quantifizierung evaluiert. Hierfür wurde eine neue Untersuchungsmethode im Bereich der Lithium-Ionen-Batterie zur besseren Detektion von Lithium-Abscheidung und Grenzflächen-Morphologie mittels Elektronenmikroskopie entwickelt.
Die Osmiumtetroxid (OsO4) Färbung ermöglichte eine deutliche Verbesserung des Materialkontrasts und erlaubte somit eine gezielte Untersuchung von graphitischen Anoden nach erfolgter Lithium-Abscheidung. Darüber hinaus konnte die selektive Reaktion des OsO4 für eine genauere Betrachtung der Solid Electrolyte Interphase genutzt werden. Eine Stabilisierung der Proben an Luft und im Elektronenstrahl konnte erreicht werden.This work sheds light on the electrochemical processes occurring at commercially processed graphitic anodes. It raises the question whether values published in literature for mostly ideal electrode systems can be readily taken for simulation and design of real electrodes in high-energy cells. A multiple step approach is given, evaluating different methods to determine electrode and material properties independently. The electrochemically active surface area was shown to be a crucial parameter for the calculation of electrode kinetics. Using exchange current densities corrected for the electrode surface area, the overall charging current in a cell could be calculated. The resulting part of lithium deposition in the charging process is strikingly high, not only at low temperatures. To further investigate lithium deposition in terms of morphology and quantity, a method was developed for graphitic anodes. Osmium tetroxide (OsO4) staining serves well as a tool to strongly increase material contrast in electron microscopy. Thus lithium dendrites could be made visible in an unprecedented manner. Furthermore, the selective chemical reaction of osmium tetroxide allows for a better investigation of the multi-layer solid electrolyte interphase as was shown in transmission electron microscopy. Using the staining method, a stabilization of the sample under air and in the electron beam could be achieved.
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Σαπουντζή, Φωτεινή. "Μελέτη της ηλεκτρικής απόδοσης και ηλεκτροχημική ενίσχυση της καταλυτικής ενεργότητας ανόδων πλατίνας και χρυσού κυψελών καυσίμου πολυμερικής μεμβράνης". Thesis, 2009. http://nemertes.lis.upatras.gr/jspui/handle/10889/1436.
Повний текст джерелаАнотація:
Οι κυψέλες καυσίμου είναι ηλεκτροχημικές διατάξεις οι οποίες επιτρέπουν την απευθείας μετατροπή της ελεύθερης χημικής ενέργειας ενός καυσίμου σε ηλεκτρική. Οι κυψέλες καυσίμου πολυμερικής μεμβράνης (ΡΕΜ) αποτελούν μία υποσχόμενη τεχνολογία που βρίσκεται κοντά στο στάδιο της εμπορευματοποίησης. Το κυριότερο καύσιμο που χρησιμοποιείται στις κυψέλες καυσίμου είναι το υδρογόνο, το οποίο παράγεται συνήθως από αναμόρφωση υδρογονανθράκων ή αλκοολών. Το μονοξείδιο του άνθρακα που παράγεται επίσης κατά την διαδικασία της αναμόρφωσης αποτελεί ένα σημαντικό άλυτο πρόβλημα στις κυψέλες ΡΕΜ, καθώς η ρόφησή του στην άνοδο της κυψέλης προκαλεί την υποβάθμιση της λειτουργίας της. Το φαινόμενο της ηλεκτροχημικής ενίσχυσης συνίσταται στην μη-φαρανταϊκή τροποποίηση της ενεργότητας ενός καταλύτη που βρίσκεται σε επαφή με έναν στερεό ηλεκτρολύτη, ως αποτέλεσμα της μετακίνησης προωθητικών ειδών από τον ηλεκτρολύτη προς την καταλυτική διεπιφάνεια μετάλλου/αερίου, που προκαλείται από την επιβολή ρεύματος ή δυναμικού μεταξύ του καταλύτη και ενός ηλεκτροδίου αναφοράς. Στην παρούσα διατριβή μελετήθηκε η ηλεκτροχημική ενίσχυση της οξείδωσης μίγματος αναμόρφωσης μεθανόλης από ανόδους πλατίνας και χρυσού μίας κυψέλης ΡΕΜ. Αποδείχθηκε πως η ηλεκτροχημική ενίσχυση επηρεάζεται σημαντικά από το διαχεόμενο διαμέσου της πολυμερικής μεμβράνης οξυγόνο, όπως επίσης και από τις συνθήκες λειτουργίας της κυψέλης καυσίμου. Επίσης μελετήθηκε η ηλεκτρική απόδοση ανόδων πλατίνας και χρυσού παρουσία CO. Προσδιορίστηκαν οι τιμές της ενθαλπίας ρόφησης του CO στα ηλεκτρόδια πλατίνας και χρυσού, καθώς και οι τιμές της ενέργειας ενεργοποίησης της απομάκρυνσης του CO από το κάθε ηλεκτρόδιο. Επίσης μελετήθηκε η επίδραση της θερμοκρασίας στο φαινόμενο της πολλαπλότητας μονίμων καταστάσεων κατά την λειτουργία κυψελών ΡΕΜ. Παρατηρήθηκε εξασθένηση του φαινομένου με την αύξηση της θερμοκρασίας, σε συμφωνία με τις προβλέψεις του μοντέλου γ.Fuel cells are electrochemical devices which convert chemical energy of a fuel directly to electricity. Polymer electrolyte membrane (PEM) fuel cells are close to commercialization. The most common fuel used is hydrogen, which is usually produced via hydrocarbons or alcohol reforming. However, during this process, carbon monoxide is formed as well, adsorbs strongly on the anode of the cell and thus impairs significantly its performance. The electrochemical promotion effect is a phenomenon where application of constant current or potential between a catalyst supported on a solid electrolyte and a reference electrode, leads to non-Faradaic changes in catalytic activity. In this thesis, it was studied the electrochemical promotion of oxidation of a methanol reformate mixture on platinum and gold anodes of a PEM fuel cell. It was found that electrochemical promotion is influenced by oxygen crossover through the polymer membrane and also by the cell operating conditions. Moreover, the electrical efficiency of platinum and gold anodes in presence of CO was studied and the values of the heat of CO adsorption on each anode and the activation energies of CO removal were estimated. Finally, the effect of temperature on the phenomenon of steady-state multiplicities was studied. It was found that increasing the temperature, the phenomenon of multiplicities is suppressed in agreement with the gama model.