Download or read book Oxidative Coupling of Methane on Sm2O3 Adsorption and Catalytic Reaction written by Yingji Huang and published by . This book was released on 1995 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oxidative Coupling of Methane Over Sm2O3 Catalysts written by Satish Nararyan Kamat and published by . This book was released on 1989 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methane Conversion by Oxidative Processes written by Wolf and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reasonable case could be made that the scientific interest in catalytic oxidation was the basis for the recognition of the phenomenon of catalysis. Davy, in his attempt in 1817 to understand the science associated with the safety lamp he had invented a few years earlier, undertook a series of studies that led him to make the observation that a jet of gas, primarily methane, would cause a platinum wire to continue to glow even though the flame was extinguished and there was no visible flame. Dobereiner reported in 1823 the results of a similar investigation and observed that spongy platina would cause the ignition of a stream of hydrogen in air. Based on this observation Dobereiner invented the first lighter. His lighter employed hydrogen (generated from zinc and sulfuric acid) which passed over finely divided platinum and which ignited the gas. Thousands of these lighters were used over a number of years. Dobereiner refused to file a patent for his lighter, commenting that "I love science more than money." Davy thought the action of platinum was the result of heat while Dobereiner believed the ~ffect ~as a manifestation of electricity. Faraday became interested in the subject and published a paper on it in 1834; he concluded that the cause for this reaction was similar to other reactions.
Download or read book Methane Conversion by Oxidative Processes written by Eduardo E. Wolf and published by Springer. This book was released on 1992 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reasonable case could be made that the scientific interest in catalytic oxidation was the basis for the recognition of the phenomenon of catalysis. Davy, in his attempt in 1817 to understand the science associated with the safety lamp he had invented a few years earlier, undertook a series of studies that led him to make the observation that a jet of gas, primarily methane, would cause a platinum wire to continue to glow even though the flame was extinguished and there was no visible flame. Dobereiner reported in 1823 the results of a similar investigation and observed that spongy platina would cause the ignition of a stream of hydrogen in air. Based on this observation Dobereiner invented the first lighter. His lighter employed hydrogen (generated from zinc and sulfuric acid) which passed over finely divided platinum and which ignited the gas. Thousands of these lighters were used over a number of years. Dobereiner refused to file a patent for his lighter, commenting that "I love science more than money." Davy thought the action of platinum was the result of heat while Dobereiner believed the ~ffect ~as a manifestation of electricity. Faraday became interested in the subject and published a paper on it in 1834; he concluded that the cause for this reaction was similar to other reactions.
Download or read book Catalytic Oxidative Coupling of Methane with Consecutive Gas phase Reaction written by Pearcey Craig David and published by . This book was released on 1994 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalytic Oxidative Coupling of Methane to C2 Hydrocarbon written by Mohd Ridzuan Nordin and published by . This book was released on 1989 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetics of Chemical Reactions written by Guy B. Marin and published by John Wiley & Sons. This book was released on 2011-08-29 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: This systematic presentation covers both experimental and theoretical kinetic methods, as well as fundamental and applied. The identification of dominant reaction paths, reaction intermediates and rate-determining steps allows a quantification of the effects of reaction conditions and catalyst properties, providing guidelines for catalyst optimization. In addition, the form in which the equations are presented allows for their straightforward implementation for scale-up and chemical reactor design purposes. Throughout, the methodologies given are illustrated by many examples.
Download or read book Catalytic Reaction Synthesis for the Partial Oxidation of Methane to Formaldehyde written by Maria-Guadalupe Cardenas-Galindo and published by . This book was released on 1993 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preparation of Magnesium Oxide Supports for Oxidative Coupling of Methane Catalysts written by Xianhe Deng and published by . This book was released on 2014 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of nano-sized magnesium oxide particles with both high and low surface areas were successfully prepared by a simple water/toluene reverse microemulsion method using triton X-45, 1-Dodecanol as surfactant. By controlling the amount of surfactant, it is possible to control the size of MgO nanoparticles from 20 nm to 50 nm. The size was confirmed by X-ray diffraction (XRD). In order to investigate the reactivity of OCM reaction over the magnesium oxide support, a series of catalysts were also synthesized. High surface area MgO samples prepared by microemulsion were used as support for Li-TbOx, where 1.75 \U+2264\ x \U+2264\ 2. In order to get the largest coverage of the MgO support and the smallest Li-TbOx particles, a nitrate precursor was used during incipient wetness impregnation, followed by calcination at 800 °C for 4 hours. Another MgO-supported Li-TbOx catalyst was prepared using the same method with the low surface area MgO nanoparticles. Low surface area MgO nanoparticles were also used as OCM catalysts after calcination at 800 °C for 4 hours. N2 adsorption (BET) results showed that the surface area of the catalysts supported on MgO nanoparticles prepared using 15 wt% Triton X-45 was as low as 1.0 m3/g, while the surface area of the catalyst prepared using MgO particle, synthesized with 15 wt% Triton X-45 and 1-Dodecanol mixture was 9.3 m3/g. Oxidative coupling of methane (OCM) catalyzed by the prepared catalysts was studied using a continuous-flow quartz reactor at atmospheric pressure, 500-800 °C at a CH4:O2 ratio of 4:1. The methane conversion reached 21.9% at 700 °C with a C2+ selectivity as high as 65.5%. Thus, a maximum C2+ yield of 13.5% was realized. However, there was a rapid deactivation during the OCM over Li-doped catalysts due to the loss of Lithium.
Download or read book Catalysis for C1 Chemistry Oxidative Coupling of Methane Using Nanofiber Catalysts and Discovery of Catalysts for Atmospheric Reduction of CO2 to Methanol written by Bahman Zohour and published by . This book was released on 2017 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this research is to explore novel catalytic material and systems for effective conversion of C1 feed. Catalysis of C1 chemistry is of critical importance for the clean production of fuels and chemicals and future energy sustainability. Herein, two processes were studied: In the first section, a comprehensive study of oxidative coupling of methane (OCM) using novel nanofiber catalysts of mixed metal oxides was undertaken and in the second section, direct catalytic conversion of carbon dioxide (CO2) to methanol was studied, which resulted in discovery of a superior catalytic system for CO2 hydrogenation to methanol. Section 1: Utilization of natural gas as an alternate chemical feedstock to petroleum has been a highly desirable but difficult goal in industrial catalysis. Accordingly, there has been a substantial interest in the oxidative coupling of methane (OCM), which allows for the direct catalytic conversion of methane into economically valuable C2+ hydrocarbons. OCM is a complex reaction process involving heterogeneous catalysis intricately coupled with gas phase reactions; hence, despite decades' worth of research, it has yet to be commercialized. The lack of progress in OCM is primarily due to the following reasons: 1. The absence of a highly active and robust catalyst that can operate at lower temperatures; and 2. Our inadequate understanding of the underlying detailed chemical kinetics mechanism (DCKM) of the OCM process, which impedes the undertaking of quantitative simulations of novel reactor configurations and/or operating strategies. To address these issues, we undertook the following program of studies: 1. Further improved the synthesis of novel nanofiber catalysts by electrospinning, building on the early discovery that La2O3-CeO2 nanofibers were highly active and robust OCM catalysts; 2. Applied our novel microprobe sampling system to OCM reactors for the acquisition of spatially resolved species concentration and temperatures profiles within the catalytic zone. Our novel sampling approach led to the important discovery that H2 is produced very early in the OCM catalytic zone, an observation that was completely missed in all prior studies. The application of our novel microprobe system to a dual-bed OCM reactor also demonstrated the feasibility to significantly improve C2+ product yields to 21% (from 16% for single bed) which we plan to further improve by considering more sequential beds; 3. Outlined development and validation of new generation of DCKM for the OCM process using the high-information content of spatial concentration profiles obtained in part 2. Most importantly, to improve the current DCKM literature by considering surface reactions that result in early H2 formation. Validated DCKM represent highly valuable numerical tools that allow for the prediction of the OCM performance of different reactor configurations operating under a broad range of conditions, e.g. high pressures, porous wall reactors etc. Consequently, this new generation of comprehensive DCKM based on the sampling profiles, detailed in this report, will be of considerable use in improving the yields of useful products in the OCM process; 4. Explore novel conditions that include oxygen-feed distributed packed bed OCM reactors and coupled catalytic and non-thermal plasma OCM reactors, again to further push the yields for useful C2+ products. The details of the proposed approach for implementing such reactor configurations and development of a new generation of DCKM for the OCM process is outlined in the future work, Chapter 4, of section 1 of the report. Section 2: Direct catalytic conversion of carbon dioxide to liquid fuels and basic chemicals, such as methanol, using solar-derived hydrogen at or near ambient pressure is a highly desirable goal in heterogeneous catalysis. When realized, this technology will pave the way for a sustainable society together with decentralized power generation. Here we report a novel class of holmium (Ho) containing multi-metal oxide Cu catalysts discovered through the application of high-throughput methods. In particular, ternary systems of Cu-GaOx-HoOy > Cu-CeOx-HoOy ~ Cu-LaOx-HoOy supported on -Al2O3 exhibited superior methanol production (10x) with less CO formation than previously reported catalysts at atmospheric pressure. Holmium was shown to be highly dispersed as few-atom clusters, suggesting that the formation of tri-metallic sites could be the key for the promotion of methanol synthesis by Ho.
Download or read book Catalytic oxidative coupling of methane with consequetive gas phase reaction written by Craig David Pearcey and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanistic Studies on the Oxidative Coupling of Methane written by Chunlei Shi and published by . This book was released on 1993 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of the Catalytic Oxidative Coupling of Methane written by S. C. Tsang and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oxidative Coupling of Methane Catalytic Studies Over Metal Oxides written by Sanjay Krishna Agarwal and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Non oxidative Coupling of Methane for Use in a Hydrogen Transporting Membrane Reactor written by Michael O'Neal Nutt and published by . This book was released on 2000 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Abstracts written by and published by . This book was released on 1995 with total page 856 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalytic Conversion of Carbon Monoxide and Methane Over Metal and Metal Oxide Catalysts written by Wenchi Liu and published by . This book was released on 2018 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalysis is of vital importance in a wide range of areas including energy processing and chemical production. Catalytic conversion of C1 sources such as carbon monoxide and methane to make hydrocarbon fuels and oxygenated products has far reaching implications especially in the context of the gradual depletion of crude oil resource and the potential surge in the natural gas production in the coming decades. The control over reaction activity and selectivity for the conversion CO and CH4 in the Fischer–Tropsch synthesis and oxidative coupling of methane (OCM) have received tremendous attention and have been proved challenging. This dissertation focuses on the catalytic conversion of CO (Fischer–Tropsch synthesis) using supported cobalt based bimetallic nanoparticle model catalysts and the oxidative coupling of methane with noble metal promoted metal oxide catalysts. Using colloidal synthesis, a series of cobalt based bimetallic nanoparticles Co–M (M = Mn, Ru, Rh, and Re) with well-defined sizes, shapes, and compositions were obtained. Detailed synthesis procedures were presented and key synthetic parameters were discussed. The as-synthesized nanoparticles were subjected to extensive in-situ X-ray spectroscopy studies using ambient pressure X-ray photoelectron spectroscopy (AP-XPS) and X-ray absorption spectroscopy (XAS) under catalytic relevant conditions. Composition wise, the results indicate the surface concentration of Co on the as-synthesized Co–M bimetallic particles is slightly less than the bulk atomic Co %. While oxidation treatment led to a slight increase of the surface Co, major effect was seen after the reduction treatment where surface segregation of the second metal resulted in a drastic decrease of the surface Co content. The effect is more pronounced at elevated reduction temperatures. Under reaction conditions, the surface compositions remained similar to those after the reduction treatment at high temperatures. Among the bimetallics tested, the Co–Mn system is relatively less susceptible to surface reconstructions induced by oxidation and reduction treatments. In addition, the reducibility of Co was also shown to be modified depending on the second metal present and Re was proved to be most efficient in leading to a facile reduction of Co. Catalytic performance of the bimetallic catalysts supported on mesoporous silica MCF–17 indicates a positive effect in the catalytic activity for Co–Rh and Co–Mn systems, while Co–Re and Co–Cu showed decreased activity. Less pronounced promotion effect of the second metal on the product distribution was observed with only a slight increase in the selectivity towards C5+ products. The selectivities for CH4 and C5+ of the various Co–M bimetallic catalysts generally resemble those of pure Co catalysts. Although in extremely low selectivity, alcohols were also formed with Co–Rh and Co–Cu bimetallic catalysts. The appearance of longer chain alcohol such as propanol, which was not present for pure Co catalysts, is an evidence for potential synergistic promotion. For oxidative coupling of methane (OCM), the promotion effect of noble metals (Pt, Ir, and Rh) on the performance of MnxOy-Na2WO4/MCF–17 catalysts was investigated. The introduction of noble metals had little effect on the surface area and phase composition of the original catalyst but led to a more reduced nature of the surface oxide species. Catalytic study revealed an enhanced selectivity towards both C2 and C3 hydrocarbons as compared to the undoped MnxOy-Na2WO4/MCF–17 catalyst in the order of Rh-doped > Ir-doped > Pt-doped samples together with a lower olefin to paraffin ratio. A more optimized strength of interaction between the carbon intermediates and the catalyst surface was suggested, which in combination with the improved reducibility of Mn and W species are believed to be responsible for the improved performance. In addition, monodispersed leaf-like manganese–tungsten–oxide (Mn–W–Ox) nanoparticles and hydroxylated hexagonal boron nitride (h-BN) were synthesized and used as novel catalysts in OCM reaction. Preliminary results indicate that the MCF–17 supported Mn–W–Ox nanoparticle catalyst showed a CH4 conversion of 5.4% and C2 selectivity of 42% with good stability over time. On the other hand, hydroxylated h-BN exhibited good activity (~20% CH4 conversion) with moderate selectivity towards C2 hydrocarbons (20%–30%). However, the hydroxylated h-BN catalysts faced serious deactivation, which was not eliminated by lowering the reaction temperature or the oxygen concentration in the reaction gas feed.
