Catalytic Ignition Of Hydrogen And Hydrogen Hydrocarbon Blends Over Noble Metals

Author : Nickolai M. Rubtsov
Publisher : Springer Nature
ISBN 13 : 303128416X
Total Pages : 230 pages
Book Rating : 4.68/5 ( download)

DOWNLOAD NOW!

Download or read book Catalytic Ignition of Hydrogen and Hydrogen-Hydrocarbon Blends Over Noble Metals written by Nickolai M. Rubtsov and published by Springer Nature. This book was released on 2023-06-01 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines the issues on noble metal influence on gaseous combustion. The book focuses on the new data on combustion processes having practical applications and includes fire safety issues in the use of noble metals in hydrogen recombiners for NPP, as well as in catalytically stabilized (CS) combustion technology including stimulation of combustion of hydrogen-blended hydrocarbons, synthesis of carbon nanotubes, and determination of catalytic ignition limits in noble metal-hydrogen-hydrocarbon systems to meet the challenges of explosion safety.

Author : Nikolai M. Rubtsov
Publisher : Springer Nature
ISBN 13 : 3030578917
Total Pages : 212 pages
Book Rating : 4.16/5 ( download)

DOWNLOAD NOW!

Download or read book Initiation and Flame Propagation in Combustion of Gases and Pyrophoric Metal Nanostructures written by Nikolai M. Rubtsov and published by Springer Nature. This book was released on 2020-10-01 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents new data on combustion processes for practical applications, discussing fire safety issues in the development of flame arresters and the use of noble metals in hydrogen recombiners for nuclear power plants. It establishes the basic principles of production of metal nanostructures, namely nanopowders of metals and compact products made of them, with the preservation of the unique properties of nanoproducts.

Author : An-Chih Yang
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.86/5 ( download)

DOWNLOAD NOW!

Download or read book Understanding and Improving Catalytic Hydrocarbon Combustion Using Well-defined Noble Metal-based Nanocrystals written by An-Chih Yang and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasingly stringent regulations on exhaust emissions create significant demands for high-performing automotive emission control catalysts. Emission control catalysts typically consist of large quantities of noble metals (e.g. platinum and palladium), which are expensive and environmentally damaging materials to extract. To develop efficient catalysts where the use of noble metals is optimized, fundamental understanding of catalytic hydrocarbon combustion would be beneficial. Yet, hydrocarbons with varying molecular structures pose a variety of challenges for this process. Therefore, this dissertation aims to study the mechanistic difference between catalytic combustion of alkane and alkene, and propose design for improved emission control catalysts. Propane and propene were chosen as the model compounds. A library of uniform Pd/Pt nanocrystal catalysts with control over composition and size were employed to study the structure-property relationships on the combustion of propene and propane. Since high levels of water always exist in automotive exhausts, the catalytic reactions in this dissertation were always performed in the presence of water, providing a complete understanding of the role of water on reaction kinetics. The first portion of this dissertation provides insights and comparison of structure-property relationships in propane and propene catalytic combustion. Synthetic conditions were optimized to generate uniform Pd/Pt nanocrystals with control over Pd/Pt ratios. Using the uniform nanocrystals, several important variables including Pd/Pt composition, support, phase and aging stability were studied. The important findings are outlined here: first, Pt-rich Pd/Pt/Al2O3 and Pt/Al2O3 were found to be the best performing samples for propene and propane combustion, respectively. From DFT calculations, propene was found to chemisorb, while propane only physisorb on the noble metal surface, which results in the opposite trends in the rate order results. Finally, equimolar Pd/Pt/Al2O3 and Pt/Al2O3 were found to exhibit the best catalytic performance after aging in propene and propane combustion, respectively. A relationship between structural sensitivity and the degree of aging resistance was found to correlate the aging stability results for both reactions. The second portion of the dissertation identifies the active sites for propene combustion. A library of Pd/Pt nanocrystals with equimolar ratio ranging from 2.3 to 10.2 nm was prepared. From the turnover frequencies and rate order results, it is observed that larger Pd/Pt nanocrystals show higher reactivity in propene combustion and sensitivity to the change in the partial pressure of reactants. We employed DFT calculations to demonstrate that water drives surface reconstruction and exposes undercoordinated sites, which are more efficient at breaking bonds in representative elementary steps in propene combustion, compared to high coordinated sites. We further developed a coordination-based model to reveal that the edge sites with (7-7) as the coordination numbers are the active-site ensemble for propene combustion. The third portion of this dissertation unravels the role of support acidity in propane combustion. A library of Pt/support with controlled Brønsted acidity was prepared with uniform Pt nanocrystals. The sample with higher Brønsted acid sites was found to have higher activity in propane combustion, as well as higher resistance to water poisoning. Using the Langmuir-Hinshelwood model, we demonstrated that supports with higher Brønsted acid site density are more hydrophobic and help reduce water coverage on Pt sites, resulting in more available sites and higher reaction rates in propane combustion. The last part of the dissertation proposes better emission control catalysts by Pt-based bimetallic nanocrystal catalysts. A seed-mediated colloidal synthesis method to produce uniform PtxM100-x (M = Cu, Co, Ni and Mn) nanocrystals with controlled size and composition was introduced. Together with DFT calculations, we created an experimental-guided volcano map to offer guidance to design catalysts with desired electronic structures, that are promising for emission control performances. Moreover, Pt/Cu was identified as the most active bimetallic sample in propene combustion. We further demonstrated that Pt/Cu have desired binding energies to C* and O*, creating more active surfaces for propene combustion. In summary, this dissertation focuses on the understanding of catalytic hydrocarbon combustion and the design of improved catalysts for emission control applications. Well-defined catalytic systems were created through the use of colloidal nanocrystals with control over size, shape and composition. With such systems, active sites and important metal-support interactions were identified for both propene combustion and propane combustion, respectively. Finally, Pt-based bimetallic nanocrystal systems were proposed to offer guidance for improved emission control catalysts.

Author : Paul Matthew Witt
Publisher :
ISBN 13 :
Total Pages : 234 pages
Book Rating : 4.8T/5 ( download)

DOWNLOAD NOW!

Download or read book The Partial Oxidation of Light Hydrocarbons Over Noble Metal Catalysts at Less Than Millisecond Contact Times written by Paul Matthew Witt and published by . This book was released on 1997 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Bo Wang
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.71/5 ( download)

DOWNLOAD NOW!

Download or read book Applications of Hydrogenation and Dehydrogenation on Noble Metal Catalysts written by Bo Wang and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogenation and dehydrogenation on Pd- and Pt- catalysts are encountered in many industrial hydrocarbon processes. The present work considers the development of catalysts and their kinetic modeling along a general and rigorous approach. The first part deals with the kinetics of selective hydrogenation, more particularly of the C3 cut of a thermal cracking unit for olefins production. The kinetics of the gas phase selective hydrogenation of methyl-acetylene (MA) and propadiene (PD) over a Pd/y-alumina catalyst were investigated in a fixed bed tubular reactor at temperatures 60 - 80 oC and a pressure of 20 bara. Hougen-Watson type kinetic equations were derived. The formation of higher oligomers slowly deactivated the catalyst. The effect of the deactivating agent on the rates of the main reactions as well as on the deactivating agent formation itself was expressed in terms of a deactivation function multiplying the corresponding rates at zero deactivation. Then, the kinetic model was plugged into the reactor model to simulate an industrial adiabatic reactor. In the second part the production of hydrogen from hydrocarbons was investigated. In both cyclohexane and decalin dehydrogenations, conversions higher than 98% could be obtained over Pd/y-alumina catalyst at temperature of 320 and 340 oC, respectively, with no apparent deactivation for 30 h and with co-feed of H2 in the feed. Except for H2 and trace amounts of side cracking products, less than 0.01%, benzene was the only dehydrogenated product in cyclohexane dehydrogenation. In the case of decalin dehydrogenation, partially dehydrogenated product, tetralin, was also formed with selectivity lower than 5%, depending on operating conditions. A rigorous Hougen-Watson type kinetic model was derived, which accounted for both the dehydrogenation of cis- and trans- decalin in the feed and also the isomerization of the two isomers. Jet A is the logic fuel in the battlefields. The dehydrogenation of Jet A can produce H2 for military fuel cell application. Although the H2 production is lower than that of steam/autothermal reforming, it eliminates the needs of high temperature and product separation operation.

Author :
Publisher :
ISBN 13 :
Total Pages : 936 pages
Book Rating : 4.76/5 ( download)

DOWNLOAD NOW!

Download or read book Fossil Energy Update written by and published by . This book was released on 1982 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Paal
Publisher : CRC Press
ISBN 13 : 9780824777746
Total Pages : 778 pages
Book Rating : 4.43/5 ( download)

DOWNLOAD NOW!

Download or read book Hydrogen Effects in Catalysis written by Paal and published by CRC Press. This book was released on 1987-11-06 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers hydrogen effects in catalysis in the broadest sense, from surface science to industrial applications. It draws the attention of the catalysis community to the importance of the phenomena of hydrogen effects both in the science and technology of catalysis.

Author : Jeanne Mager Stellman
Publisher : International Labour Organization
ISBN 13 : 9789221098164
Total Pages : 1266 pages
Book Rating : 4.68/5 ( download)

DOWNLOAD NOW!

Download or read book Encyclopaedia of Occupational Health and Safety written by Jeanne Mager Stellman and published by International Labour Organization. This book was released on 1998 with total page 1266 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author :
Publisher :
ISBN 13 :
Total Pages : 1460 pages
Book Rating : 4.26/5 ( download)

DOWNLOAD NOW!

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Author : Edward Bradford Maxted
Publisher :
ISBN 13 :
Total Pages : 124 pages
Book Rating : 4.87/5 ( download)

DOWNLOAD NOW!

Download or read book Catalytic hydrogenation and reduction written by Edward Bradford Maxted and published by . This book was released on 1919 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: