Download or read book Development of a Bifunctional Core shell Nanocatalyst written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Core Shell and Yolk Shell Nanocatalysts written by Hiromi Yamashita and published by Springer Nature. This book was released on 2021-05-15 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces recent progress in preparation and application of core-shell and yolk-shell structures for attractive design of catalyst materials. Core-shell nanostructures with active core particles covered directly with an inert shell can perform as highly active and selective catalysts with long lifetimes. Yolk-shell nanostructures consisting of catalytically active core particles encapsulated by hollow materials are an emerging class of nanomaterials. The enclosed void space is expected to be useful for encapsulation and compartmentation of guest molecules, and the outer shell acts as a physical barrier to protect the guest molecules from the surrounding environment. Furthermore, the tunability and functionality in the core and the shell regions can offer new catalytic properties, rendering them attractive platform materials for the design of heterogeneous catalysts. This book describes the recent development of such unique nanostructures to design effective catalysts which can lead to new chemical processes. It provides an excellent guide for design and application of core-shell and yolk-shell structured catalysts for a wide range of readers working on design of attractive catalysts, photocatalysts, and electrocatalysts for energy, environmental, and green chemical processes.

Download or read book Nanotechnology in Catalysis written by Bert Sels and published by John Wiley & Sons. This book was released on 2017-06-20 with total page 1500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflecting the R&D efforts in the field that have resulted in a plethora of novel applications over the past decade, this handbook gives a comprehensive overview of the tangible benefits of nanotechnology in catalysis. By bridging fundamental research and industrial development, it provides a unique perspective on this scientifically and economically important field. While the first three parts are devoted to preparation and characterization of nanocatalysts, the final three provide in-depth insights into their applications in the fine chemicals industry, the energy industry, and for environmental protection, with expert authors reporting on real-life applications that are on the brink of commercialization. Timely reading for catalytic chemists, materials scientists, chemists in industry, and process engineers.

Download or read book Development of Platinum copper Core shell Nanocatalyst on Multi walled Carbon Nanotubes for Proton Exchange Membrane Fuel Cells written by Anthony Adame and published by . This book was released on 2012 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: With a recent shift to a more environmentally conscious society, low-carbon and non-carbon producing energy production methods are being investigated and applied all over the world. Of these methods, fuel cells show great potential for clean energy production. A fuel cell is an electrochemical energy conversion device which directly converts chemical energy into electrical energy. Proton exchange membrane fuel cells (PEMFCs) are a highly researched energy source for automotive and stationary power applications. In order to produce the power required to meet Department of Energy requirements, platinum (Pt) must be used as a catalyst material in PEMFCs. Platinum, however, is very expensive and extensive research is being conducted to develop ways to reduce the amount of platinum used in PEMFCs. In the current study, three catalyst synthesis techniques were investigated and evaluated on their effectiveness to produce platinum-on copper (Pt@Cu) core-shell nanocatalyst on multi-walled carbon nanotube (MWCNT) support material. These three methods were direct deposition method, two-phase surfactant method, and single-phase surfactant method, in which direct deposition did not use a surfactant for particle size control and the surfactant methods did. The catalyst materials synthesized were evaluated by visual inspection and fuel cell performance. Samples which produced high fuel cell power output were evaluated using transmission electron microscopy (TEM) imaging. After evaluation, it was concluded that the direct deposition technique was effective in synthesizing Pt@Cu core-shell nanocatalyst on MWCNTs support when a rinsing process was used before adding platinum. The peak power density achieved by the rinsed core-shell catalyst was 618 mW.cm-2, 13 percent greater than that of commercial platinum-carbon (Pt/C) catalyst. Transmission electron microscopy imaging revealed the core-shell catalyst contained Pt shells and platinum-copper alloy cores. Rinsing with deionized (DI) water was shown to be a crucial step in core-shell catalyst deposition as it reduced the number of platinum colloids on the carbon nanotube surface. After evaluation, it was concluded that the two-phase surfactant and single-phase surfactant synthesis methods were not effective at producing core-shell nanocatalyst with the parameters investigated.

Download or read book New Core shell Nanocatalyst Design for Oxygen Reduction Reaction written by 莊玉 and published by . This book was released on 2018 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comprehensive Natural Products Chemistry written by Derek Barton and published by Newnes. This book was released on 1999-02-18 with total page 11380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Natural Products Chemistry

Download or read book Development of Novel Biodegradable Core shell Nanoparticles as Carriers for Gene Delivery written by Mimi Hetti and published by . This book was released on 2010 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Development of Novel Cost effective Nanocatalysts for Hydrogenation Purposes written by Stephany García and published by . This book was released on 2014 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research has focused on the controlled synthesis of mono- and bimetallic noble metal nanoparticles (MNPs) for catalytic applications. MNPs such as Au, Rh, Pd, Pt and Ag have been synthesized with the aid of microwave heating ([mu] wH) which provides a greener heating method. Furthermore, it provides kinetic control over the size, shape and composition of these NPs. Several bimetallic core-shell NPs have also been synthesized using this method, making it possible to overcome thermodynamic energy barriers that arise with this type of assembly when the metals used, greatly differ in surface energy and lattice constant. It has also been possible to tune the shell thickness of the NPs in order to have an impact in the kinetics of hydrogenation catalytic processes performed. ‘Non-equilibrium’ alloyed structures have been generated in the nanoscale as well, with the aid of [mu] wH. These types of nanostructures are of particular interest because due to synergistic effects, the mixture of heteroatoms resulted in enhancement of catalytic activity and in chemical/physical stability in comparison to their monometallic components. These Rh[subscript x]M100−[subscript x] (M = Ag or Au) NPs displayed remarkable catalytic activities, as compared to pure Rh NPs. Furthermore, the composition was systematically varied in order to optimize the catalytic properties. These experimental observations were supported by theoretical modeling and calculations (DFT). Thus, very cost effective nanocatalysts have been prepared by diluting relatively inexpensive and catalytically inactive metals, such as Au and Ag, with active precious metals such as Rh. This research has also focused on the design and synthesis of novel capping agents for small metal NPs. The ultimate goal is to generate self-activating particles that when placed in a hydrogenation catalysis environment (reducing conditions), these will chemically rid themselves of the stabilizing agents in a clean and controlled fashion under mild conditions. Thus, naked NPs that are extremely active and still have defined facets that can potentially provide selectivity in certain catalytic processes will be left behind. These NPs are more cost-effective and have a lower impact on the environment due to the milder reaction conditions applied, yielding great candidates for hydrogenation catalysts in industrial processes.

Download or read book Thermally Stable Nanocatalyst for High Temperature Reactions written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in colloidal synthesis enabled the precise control of size, shape and composition of catalytic metal nanoparticles, allowing their use as model catalysts for systematic investigations of the atomic-scale properties affecting catalytic activity and selectivity. The organic capping agents stabilizing colloidal nanoparticles, however, often limit their application in high-temperature catalytic reactions. Here we report the design of a high-temperature stable model catalytic system that consists of Pt metal core coated with a mesoporous silica shell (Pt@mSiO2). While inorganic silica shells encaged the Pt cores up to 750 C in air, the mesopores directly accessible to Pt cores made the Pt@mSiO2 nanoparticles as catalytically active as bare Pt metal for ethylene hydrogenation and CO oxidation. The high thermal stability of Pt@mSiO2 nanoparticles permitted high-temperature CO oxidation studies, including ignition behavior, which was not possible for bare Pt nanoparticles because of their deformation or aggregation. The results suggest that the Pt@mSiO2 nanoparticles are excellent nanocatalytic systems for high-temperature catalytic reactions or surface chemical processes, and the design concept employed in the Pt@mSiO2 core-shell catalyst can be extended to other metal-metal oxide compositions.

Download or read book Theoretical Study of Correlation Between Structure and Function for Nanoparticle Catalysts written by Liang Zhang and published by . This book was released on 2014 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: The science and technology of catalysis is more important today than at any other time in our history due to the grand energy and environment challenges we are facing. With the explosively growth of computation power nowadays, computer simulation can play an increasingly important role in the design of new catalysts, avoiding the costly trail-and-error attempts and facilitating the development cycle. The goal to inverse design of new materials with desired catalytic property was once far off, but now achievable. The major focus of this dissertation is to find the general rules that govern the catalytic performance of a nanoparticle as the function of its structure. Three types of multi-metallic nanoparticles have been investigated in this dissertation, core-shell, random alloy and alloy-core@shell. Significant structural rearrangement was found on Au@Pt and Pd@Pt nanoparticle, which is responsible for a dramatic improvement in catalytic performance. Nonlin- ear binding trends were found and modeled for random alloy nanoparticles, providing a prescription for tuning catalytic activity through alloying. Studies of ORR on Pd/Au random alloy NP and hydrogenation reaction on Rh/Ag random alloy NP revealed that binding on individual ensemble should be in- vestigated when large disparity of adsorbate affinity is presented between two alloying elements. In the alloy-core@shell system, I demostrated a general linear correlations between the adsorbate binding energy to the shell of an alloy-core@shell nanoparticle and the composition of the core. This relation- ship allows for interpolation of the properties of single-core@shell particles and an approach for tuning the catalytic activity of the particle. A series of promising catalysts were then predicted for ORR, HER and CO oxidation. As a first attempt to bridge the material gap, bimetallic nano clus- ter supported on CeO2(111) was investigated for CO oxidation. A strong support-metal interaction induces a preferential segregation of the more reac- tive element to the NC-CeO2 perimeter, generating an interface with the Au component. (Au-Cu)/CeO2 was found to be optimal for catalyzing CO oxida- tion via a bifunctional mechanism. O2 preferentially binds to the Cu-rich sites whereas CO binds to the Au-rich sites. A method called distributed replica dynamics (DRD) is proposed at last to utilize enormous distributed computing resources for molecular dynamics simulations of rare-event in chemical reac- tions. High efficiency can be achieved with an appropriate choice of N [subscript rep] and t [subscript rep] for long-time MD simulation.

Download or read book Development and Impact of Precisely Tunable Mesoporous Silica Encapsulated Core Shell Nanoparticles written by Ellis Hammond-Pereira and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work concerns the development of a precisely-tunable silica-encapsulated gold core-shell nanoparticle (CSNP) catalyst, and the impacts of tuning on catalytic performance. Confining nanoparticles within a porous structure is a valuable technique to reduce agglomeration, helping to preserve their typically high catalytic activity despite harsh reaction conditions. Further investigations reveal that beyond maintaining particle size, the presence of a pore structure itself fundamentally improves catalysis. Research elucidating this effect is hindered by the nature of traditional porous catalysts, whose nanoparticles grow to match the diameter of the pore. Diffusing nanoparticles random distances into existing pores also obfuscates the concept of pore length. Absent methods to control these morphological parameters individually, the specific mechanism by which pore constraint improves catalysis has remained unclear. CSNPs present an opportunity to investigate the effects of pore geometry on catalysis, unconstrained by either of these problems. Pores are freely scalable without influencing nanoparticle size, and exhibit concrete, measurable pore lengths.The catalytic improvement of pore constraint, comparing CSNPs to non-porous control catalysts, is presented. The presence of a pore environment improved both benzyl alcohol conversion and selectivity compared to a control catalyst using the same support material. CSNPs exhibited higher activity and comparable selectivity to supported nanoparticles whose strong metal-support interactions intrinsically aid performance.The ability to individually tune the pore length and pore diameter of silica-encapsulated gold core-shell nanoparticles via seeded encapsulation method is demonstrated. This technique facilitated the synthesis of CSNP samples with increasing pore length, and CSNP samples with increasing pore diameter. When benchmarked using benzyl alcohol oxidation, CSNPs with longer pores increased catalytic activity exclusively through the formation of the desired aldehyde product. By contrast, increasing pore diameter increased the formation of the aldehyde and ester products unselectively. The isolated nature of these orthogonal studies, uniquely enabled by the updated CSNP synthesis, demonstrates with clarity the impact of pore-constraint on catalysis. The ability to influence catalytic behavior on an active surface, exclusively via manipulation of a molecule's path to said surface, is a powerful tool, one merely suggested by preceding literature. The direct observation of such behavior is unprecedented, and has immediate applicability across the catalysis field.Furthermore, these findings align with several molecular confinement studies which observe the formation of concentric microphases within comparable pore environments. Not only does this provide a concrete path for future work, but also has the potential to connect two fundamentally related fields (molecular confinement and porous catalysis), which largely operate in isolation.

Download or read book Nanocatalysts in Biofuel Process Optimization written by Mohammad Rehan and published by Frontiers Media SA. This book was released on 2021-11-26 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Magnetic Nanostructured Materials written by Ahmed A. El Gendy and published by Elsevier. This book was released on 2018-06-29 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Nanostructured Materials: From Lab to Fab presents a complete overview of the translation of nanostructured materials into realistic applications, drawing on the most recent research in the field to discuss the fundamentals, synthesis and characterization of nanomagnetics. A wide spectrum of nanomagnetic applications is included, covering industrial, environmental and biomedical fields, and using chemical, physical and biological methods. Materials such as Fe, Co, CoxC, MnGa, GdSi, ferrite nanoparticles and thin films are highlighted, with their potential applications discussed, such as magnetic refrigeration, energy harvesting, magnetic sensors, hyperthermia, MRI, drug delivery, permanent magnets, and data storage devices. Offering interdisciplinary knowledge on the materials science of nanostructured materials and magnetics, this book will be of interest to researchers in materials science, engineering, physics and chemistry with interest in magnetic nanomaterials, as well as postgraduate students and professionals in industry and government. - Provides interdisciplinary knowledge on the materials science of nanostructured materials and magnetics - Aids in the understanding of complex fundamentals and synthesis methods for magnetic nanomaterials - Includes examples of real applications - Shows how laboratory work on magnetic nanoparticles connects to industrial implementation and applications

Download or read book Transmission Electron Microscopy Characterization of Nanomaterials written by Challa S.S.R. Kumar and published by Springer Science & Business Media. This book was released on 2013-12-09 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt: Third volume of a 40volume series on nanoscience and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about Transmission electron microscopy characterization of nanomaterials. Modern applications and state-of-the-art techniques are covered and make this volume an essential reading for research scientists in academia and industry.

Download or read book Nano catalysts for Energy Applications written by Rohit Srivastava and published by CRC Press. This book was released on 2021-07-29 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises of chapters based on design of various advanced nano-catalysts and offers a development of novel solutions for a better sustainable energy future. The book includes all aspects of physical chemistry, chemical engineering and material science. The advances in nanoscience and nanotechnology help to find cost-effective and environmentally sound methods of converting naturally inspired resources into fuels, chemicals and energy. The book leads the scientific community to the most significant development in the focus research area. It provides a broad and in-depth coverage of design and development advanced nano-catalyst for various energy applications.

Download or read book Functionalized Nanomaterials for Catalytic Application written by Chaudhery Mustansar Hussain and published by John Wiley & Sons. This book was released on 2021-07-21 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functionalized Nanomaterials for Catalytic Application

Download or read book Nanomaterials and Devices written by Donglu Shi and published by Elsevier. This book was released on 2014-09-18 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introducing the fields of nanomaterials and devices, and their applications across a wide range of academic disciplines and industry sectors, Donglu Shi bridges knowledge acquisition and practical work, providing a starting point for the research and development of applications. The book describes characterization of nanomaterials, their preparation methods and performance testing techniques; the design and development of nano-scale devices; and the applications of nanomaterials, with examples taken from different industry sectors, such as lighting, energy, bioengineering and medicine / medical devices. Key nanomaterial types are covered, such as carbon nanotubes, nanobiomaterials, nano-magnetic materials, semiconductor materials and nanocomposites. Shi also provides detailed coverage of key emerging technologies such as DNA nanotechnology and spintronics. The resulting text is equally relevant for advanced students (senior and graduate) and for engineers and scientists from a variety of different academic backgrounds working in the multi-disciplinary field of nanotechnology. - Provides detailed guidance for the characterization of nanomaterials, their preparation, and performance testing - Explains the principles and challenges of the design and development of nano-scale devices - Explores applications through cases taken from a range of different sectors, including electronics, energy and medicine.