Download or read book Synthesis Characterization and Preparation of Platinum ruthenium Catalysts written by Hong Yian Lin and published by . This book was released on 1998 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization and Analysis of Platinum based Multiphase Catalysts for Direct Ethanol Fuel Cells written by Jonathan R. Mann and published by . This book was released on 2006 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Platinum-based particles are synthesized via the polyol process in an effort to include various metal oxides in a multi-phase catalyst for the direct ethanol fuel cell anode. Among Eu, In, La and Nb, no single metal oxide with platinum yields open circuit potentials or maximum current densities as high as tin oxide with platinum. For this reason, particles with platinum, tin oxide and the oxide of a third metal were developed. Platinum tin/indium oxide slightly outperforms platinum tin oxide. The particles are characterized by TEM, EDX, XRD and ICP. The metal oxides and the platinum are located together in one particle, uniformly 5.3 nm in diameter. ICP analysis indicates that the catalysts are 20% platinum on carbon and the metals of the oxides are on the order of 1-2% by mass. The catalytic abilities of the particles were evaluated in a single cell direct ethanol fuel cell where polarization curves were taken up to 130°C, and oxidation products were analyzed by gas chromatography. Open circuit voltages of as high as 0.82 V were obtained for platinum tin/indium oxide catalysts and current densities as high as 0.4 A cm-2 were seen. The cells produced large amounts of acetaldehyde and acetic acid, as well as small amounts of methanol and carbon dioxide. A spillover mechanism is proposed for the oxidation of ethanol to CO2 on these platinum/metal oxide catalysts.
Download or read book Synthesis and Characterization of Platinum Group Metal Free Catalysts for the Electro Catalytic Oxygen Reduction Reaction written by Fang Luo and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Platinum Based Catalysts for Fuel Cells written by Sonam Patel and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Platinum (Pt) and platinum alloys have attracted wide attention as catalysts to attain high performance to increase the power density and reduce the component cost of polymer electrolyte membrane fuel cells (PEMFCs). Extensive research has been conducted in the areas of new alloy development and understanding of mechanisms of electrochemical oxygen reduction reaction (ORR). The durability of PEMFCs is also a major barrier to the commercialization of these fuel cells. Recent studies have suggested that potential cycling can gradually lead to loss of active surface area due to Pt dissolution and nanoparticle grain growth [1]. In this thesis we report a one-step synthesis of highly-dispersed Pt nanoparticles and Pt- Cobalt supported on Ketjen carbon black (20% Pt/C & 20% Pt3Co/C) as electro-catalysts for PEMFCs. Pt particles with size in the range of ~ 2.6nm (Pt/C) and 3.9 nm (Pt3Co/C) were obtained through adsorption on carbon supports and subsequently thermal decomposition of platinum acetylacetonate (Pt(acac)2). A comparative characterization analysis, including X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), FT-iR, EDAX, cyclic voltammetry (CV), and oxygen reduction reaction (ORR) activity, was performed on the synthesized and commercial (46.5wt% TKK) catalysts. The analysis was to reveal the Pt dispersion on the carbon support, particle size and distribution, electrochemical surface area (ECA), and ORR activities of these catalysts. It was found that the synthesized Pt/C showed similar particle size to that of the TKK catalysts (2.6nm and 2.7nm, respectively), but narrower particle size distribution; while the particle size for Pt3Co/C was found to be ~3.9 nm. Accelerated durability tests (ADT) under potential cycles were also performed for Pt/C and TKK to study the electrochemical degradation of the catalysts in corrosive environments. The ADTs revealed that the two catalysts (Pt/C & TKK) were comparable with respect to degradation in ECA and ORR activities. Initial electrochemical evaluation of Pt3Co/C was conducted, but durability studies were not attempted in this thesis due to its worse ORR kinetics than those of the Pt/C catalyst. From the experimental data, it was found that particle size impacted negatively the ECA and ORR activity of the catalysts.
Download or read book Ruthenium in Catalysis written by Pierre H. Dixneuf and published by Springer. This book was released on 2014-10-18 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Organometallic Chemistry presents critical overviews of research results in organometallic chemistry. As our understanding of organometallic structure, properties and mechanisms increases, new ways are opened for the design of organometallic compounds and reactions tailored to the needs of such diverse areas as organic synthesis, medical research, biology and materials science. Thus the scope of coverage includes a broad range of topics in pure and applied organometallic chemistry, where new breakthroughs are being achieved that are of significance to a larger scientific audience. The individual volumes of Topics in Organometallic Chemistry are thematic. Review articles are generally invited by the volume editors.
Download or read book Synthesis Characterization and Biological Activity of Hydroxylated Diphosphine Complexes of Ruthenium Platinum and Palladium written by Ana Clara Zampirolli Leal and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preparation of Catalysts VII written by R. Maggi and published by Elsevier. This book was released on 1998-08-17 with total page 1007 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings of the VIIth International Symposium on the Scientific Bases for the Preparation of Heterogeneous Catalysts, are in line with the general scope of this series of events. Emphasis in all Symposia has been on the scientific aspects of the preparation of new and industrial catalysts, or on new methods of preparation, rather than on the catalytic reactions in which such solids are ultimately used. In the present context, the catalytic event itself has only been considered as another, though often decisive, method of catalyst characterization.
Download or read book The Synthesis Characterization and Catalytic Reaction Studies of Monodisperse Platinum Nanoparticles in Mesoporous Oxide Materials written by Robert Martin Rioux and published by . This book was released on 2006 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: A catalyst design program was implemented in which Pt nanoparticles, either of monodisperse size and/or shape were synthesized, characterized and studied in a number of hydrocarbon conversion reactions. The novel preparation of these materials enables exquisite control over their physical and chemical properties that could be controlled (and therefore rationally tuned) during synthesis. The ability to synthesize rather than prepare catalysts followed by thorough characterization enable accurate structure-function relationships to be elucidated. Pt nanoparticles (1.7--7.1 nm) are synthesized by solution phase reduction methods in which Pt precursors are reduced in protic solvents in the presence of a surface templating polymer, which serves to stabilize the metal nanoparticles in solution. Particle size can be controlled during synthesis by altering either the PVP: Pt salt ratio, reaction media and by seeded growth methods. After Pt nanoparticles are synthesized, their size and morphology are confirmed with transmission electron microscopy and x-ray diffraction. Low power sonication in either aqueous or organic solvent was utilized to disperse Pt nanoparticles within the mesoporous metal oxide matrix. This method of catalyst synthesis is named capillary inclusion (CI). An alternative approach to catalyst synthesis combines the hydrothermal synthesis of mesoporous silica with Pt nanoparticle synthesis in the same solution. Synthesis under neutral conditions led to a catalyst in which the nanoparticles were highly dispersed throughout the catalyst matrix. This method of catalyst synthesis called nanoparticle encapsulation (NE) ensured that Pt nanoparticles were located on the internal pore surface of the mesoporous silica. Catalysts were characterized by transmission electron microscopy (TEM), x-ray diffraction (XRD), small angle x-ray scattering (SAXS) and physical adsorption to determine metal particle size and mesoporous structure. The surface chemistry of the nanoparticle surface was studied by infrared spectroscopy, selective gas adsorption (chemisorption) and catalytic reactivity studies. During nanoparticle synthesis, PVP is added to the solution to stabilize the platinum nanoparticles against aggregation. This polymer remains bound to the nanoparticle surface after catalyst synthesis and must be removed before catalytic reactions. Calcination of the catalyst at high temperature (623--723 K) for long time periods (24--36 hours) followed by reduction was initially used to clean the Pt surface. (Abstract shortened by UMI.)
Download or read book Dinuclear Ruthenium and Platinum Complexes Design Synthesis Characterization and Potential Applications written by Gat︠an LeClair and published by . This book was released on 2008 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization and Catalytic Application of Novel and Immobilized Palladium and Ruthenium Complexes written by Matthew Ryan Sheets and published by . This book was released on 2008 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ruthenium Catalysts and Fine Chemistry written by Christian Bruneau and published by Springer Science & Business Media. This book was released on 2004-06-30 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions by numerous experts
Download or read book Synthesis and Characterization of Hydrido ruthenium and Platinum Carbonyl Complexes written by Rosemarie Szostak and published by . This book was released on 1982 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Supported Rhenium Iridium and Platinum Catalysts written by Scott K. Purnell and published by . This book was released on 1994 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Platinum based Multi component Catalysts for Direct Methanol Fuel Cells written by Li Ren and published by . This book was released on 2007 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In the thesis work, Pt-based binary, ternary, quaternary alloy anode catalysts supported on sonochemically treated multi-walled carbon nanotubes (CNTs) were synthesized with ethylene glycol reduction of corresponding metal chloride salts. Inductively coupled plasma-mass spectroscopy (ICP-MS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) were used for catalyst characterization. Cyclic voltammetry for methanol oxidation and CO stripping were used to evaluate the performance of the catalysts. PtRu nanoparticles supported on CNTs (PtRu/CNT) were prepared under a series of pHs. It was found that the PtRu particle size, composition, and catalytic activity were all sensitive to the deposition pHs. CO stripping results provided the peak potential and active surface area for each catalyst. The atomic ratios tended to approach the predetermined ratio 1:1 with the increase of pH, which is favored by bi-functional catalytic mechanism. PtRu catalysts prepared at higher pHs presented better electrochemical activity toward methanol oxidation. Humidified oxygen treatment of the PtRu/CNT led to improved activity of the catalysts toward methanol electro-oxidation, implying that Ru hydroxide is better than Ru as a co-catalyst. PtRu, PtOs, PtRuOs, and PtRuOsIr nanoparticles supported on CNTs with atomic ratios of Pt:Ru (tr:46), Pt:Os (80:20), Pt:Ru:Os (54:36:10), and Pt:Ru:Os:Ir (44:36:10:5) were prepared. Cyclic voltammetry for the methanol oxidation and CO stripping at the catalysts showed that PtRu/CNT and PtRuOsIr/CNT have the best performance toward methanol oxidation, PtRuOs/CNT has the lowest activity, but PtOs/CNT exhibits better catalytic activity only at potential or 0.73 V"--Abstract, leaf iii.
Download or read book Synthesis and Characterization of Platinum Based Fuel Cell Catalysts written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Bimetallic Platinum gold Catalysts written by Corina Mihut and published by . This book was released on 2002 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Ruthenium II and Platinum IV Complexes with Anionic Heteroatomic Ligands written by Joshua Taylor Gurkin and published by . This book was released on 2009 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: platinum(IV), ruthenium(II), C-H activation, pyrazolyl alkanes.
