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Synthesis Catalytic Activity Measurement And Characterization Of Doped Cobalt Oxide Catalysts For Toxic Gases Emission Treatment
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Book Synopsis Synthesis, Catalytic Activity Measurement and Characterization of Doped Cobalt Oxide Catalysts for Toxic Gases Emission Treatment by : Swee Kuan Yen
Download or read book Synthesis, Catalytic Activity Measurement and Characterization of Doped Cobalt Oxide Catalysts for Toxic Gases Emission Treatment written by Swee Kuan Yen and published by . This book was released on 2004 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Iron and Cobalt Catalysts by : Wilson D. Shafer
Download or read book Iron and Cobalt Catalysts written by Wilson D. Shafer and published by MDPI. This book was released on 2020-06-23 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the turn of the last century when the field of catalysis was born, iron and cobalt have been key players in numerous catalysis processes. These metals, due to their ability to activate CO and CH, haev a major economic impact worldwide. Several industrial processes and synthetic routes use these metals: biomass-to-liquids (BTL), coal-to-liquids (CTL), natural gas-to-liquids (GTL), water-gas-shift, alcohol synthesis, alcohol steam reforming, polymerization processes, cross-coupling reactions, and photocatalyst activated reactions. A vast number of materials are produced from these processes, including oil, lubricants, waxes, diesel and jet fuels, hydrogen (e.g., fuel cell applications), gasoline, rubbers, plastics, alcohols, pharmaceuticals, agrochemicals, feed-stock chemicals, and other alternative materials. However, given the true complexities of the variables involved in these processes, many key mechanistic issues are still not fully defined or understood. This Special Issue of Catalysis will be a collaborative effort to combine current catalysis research on these metals from experimental and theoretical perspectives on both heterogeneous and homogeneous catalysts. We welcome contributions from the catalysis community on catalyst characterization, kinetics, reaction mechanism, reactor development, theoretical modeling, and surface science.
Book Synopsis The Development of Lanthanide Doped Cobalt Based Catalysts Towards NOx Reduction by : Sharmilah Kuppusami
Download or read book The Development of Lanthanide Doped Cobalt Based Catalysts Towards NOx Reduction written by Sharmilah Kuppusami and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Cobalt Catalysis in Organic Synthesis by : Marko Hapke
Download or read book Cobalt Catalysis in Organic Synthesis written by Marko Hapke and published by John Wiley & Sons. This book was released on 2020-04-06 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a much-needed account of the formidable "cobalt rush" in organic synthesis and catalysis Over the past few decades, cobalt has turned into one of the most promising metals for use in catalytic reactions, with important applications in the efficient and selective synthesis of natural products, pharmaceuticals, and new materials. Cobalt Catalysis in Organic Synthesis: Methods and Reactions provides a unique overview of cobalt-catalysed and -mediated reactions applied in modern organic synthesis. It covers a broad range of homogeneous reactions, like cobalt-catalysed hydrogenation, hydrofunctionalization, cycloaddition reactions, C-H functionalization, as well as radical and biomimetic reactions. First comprehensive book on this rapidly evolving research area Covers a broad range of homogeneous reactions, such as C-H activation, cross-coupling, synthesis of heterocyclic compounds (Pauson-Khand), and more Chapters on low-valent cobalt complexes as catalysts in coupling reactions, and enantioselective cobalt-catalyzed transformations are also included Can be used as a supplementary reader in courses of advanced organic synthesis and organometallic chemistry Cobalt Catalysis in Organic Synthesis is an ideal book for graduates and researchers in academia and industry working in the field of synthetic organic chemistry, catalysis, organometallic chemistry, and natural product synthesis.
Book Synopsis Catalytic Conversion of Carbon Monoxide and Methane Over Metal and Metal Oxide Catalysts by : Wenchi Liu
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.
Book Synopsis Recent Advances in Cobalt and Related Catalysts by : John Vakros
Download or read book Recent Advances in Cobalt and Related Catalysts written by John Vakros and published by Mdpi AG. This book was released on 2021-09-08 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, cobalt and related catalysts are very attractive as they provide many advantages, such as low cost and high activity, in a variety of applications. Cobalt catalysts are among the most active catalysts for Fischer-Tropsch synthesis and they promote the catalytic activity of the hydrodesulfurization catalysts. They also found other significant applications in environmental protection such as oxidation of volatile organic compounds, VOC, persulfate activator, ammonia synthesis, electrocatalysis and many more. Cobalt catalysts are active, stable and exhibit significant oxidation-reduction activity, as the Co can be found either as Co(II) or Co(III). Additionally, many molecules can interact with the cobalt supported phase by co-ordination due to partially filled d-orbital. Co-catalysts can be supported in almost all the inorganic supports such as alumina, titania, zeolites, etc. The cobalt oxide phase can be stabilized on the surface of the support due to variable interactions between the support and cobalt phase. These interactions are crucial for catalytic activity and can be regulated by proper selection of the preparation parameters such as the type of support, the Co loading, impregnation method and thermal conditions.
Book Synopsis Metal Oxide Catalysts for Green Applications by : Tiberiu Popa
Download or read book Metal Oxide Catalysts for Green Applications written by Tiberiu Popa and published by . This book was released on 2009 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cobalt oxide compounds are effective in decomposing N2O. A series of supported cobalt oxide catalysts with different amounts of cobalt oxide were synthesized by incipient wetness impregnation of gamma-alumina and by coprecipitation with precursors of cerium oxide. Each of the series of alkali metals (lithium, sodium, potassium, rubidium, and cesium) were added to each of the catalysts of varying cobalt oxide content to examine the promotion effect of these metals. The catalysts were characterized by surface area analysis, temperature programmed reduction, X-ray Diffraction, and UV-visible spectroscopy. Catalytic activity was investigated for the decomposition of both NO and N2O. The ceria-supported catalysts were significantly more active than the alumina-supported ones. With the same amount of cobalt, the ceria-supported catalysts produced equal reaction rates at around 200 K lower temperatures than the alumina-supported catalysts. All catalysts showed good activity for direct N2O decomposition over a temperature range of 573 K to 973 K. At 873 K, the reaction rate for alumina supported catalysts had values depending on cobalt loading between 1.4 and 1.7 x 10 -7 mol/(s g catalyst), while at the same temperature for ceria supported catalysts the values are 3.3 x 10 -7 mol/(s g catalyst). None of the catalysts maintained activity with NO as reactant, presumably forming surface nitrates or nitrites stoichiometrically without any catalytic turnover. The best alumina supported catalysts contained no alkali. Small amounts (0.01-0.05 atom %) of potassium or rubidium decreased the rate of N2O decomposition. The Water Gas Shift (WGS) project has as a goal to develop an integrated system to produce high purity hydrogen and generating CO2 at the purity required by its use in industry or needed for sequestration. As part of the present work, the production of an improved monolithic WGS catalyst that provides efficient conversion of CO and structural support for a stacked assembly of membranes was studied. This can be subdivided in two major parts: (1) The synthesis of more active catalysts having good compatibility with the monolithic support. The catalysts were prepared by adding alumina or ceria in the iron oxide based WGS catalyst; (2) The production and use of ceramic supports for the water gas shift catalysts; Alumina (Al2O3) was added as a component of conventional High Temperature. Addition of between 10 and 20 wt% alumina increased the catalyst activity and thermal stability, with approximately 15 wt% alumina addition being optimum as its reaction rate (normalized per mass) was 74% higher than the reference catalyst. The effect of alumina addition was greater than the surface area increase alone, which suggests that alumina increases the activity of the iron oxide domains, likely through an increase in reducibility, as shown by the TPR results. A series of high temperature water gas shift catalysts containing iron, chromia, and copper oxides were prepared with small amounts of added ceria in the system Fe-Cr-Cu-Ce-O. The catalysts were prepared by coprecipitation and compared with a reference catalyst containing 88 wt% FeOx, 8 wt% Cr2O3, and 4 wt% CuO. Unlike the other catalysts studied, the catalysts containing more than 85 wt% ceria do not exhibit the typical logarithmic decay curve in rate with time under reaction conditions, but instead show a minimum followed by an increased rate. This behavior, in addition to observations of the catalyst morphology from the SEM images, suggests that iron oxide-chromia is deposited on the surface of ceria and the magnetite-ceria interface is important for catalyst performance. Mullite porous ceramic disks were prepared by impregnation of foam rubber (to provide porosity) with a suspension containing kaolin and alumina and calcined at temperatures ranging between 1300 and 1400°C. The catalyst deposited on ceramic showed stability to oxygen and atmospheric humidity when exposed to air during handling between tests, losing only 17% of the activity it displayed at the end of the first test. A cordierite honeycomb type ceramic monolith was also impregnated. The monoliths are commercially available and provide better flow hydrodynamics for the reaction.
Book Synopsis Characterization of Cobalt Based Catalysts for Ethanol Steam Reforming by : Shih-yi Lin
Download or read book Characterization of Cobalt Based Catalysts for Ethanol Steam Reforming written by Shih-yi Lin and published by . This book was released on 2009 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Preferential Oxidation of Carbon Monoxide Over Heat Treated Swellable Organically Modified Silica Supported Cobalt Oxide Catalyst by : Dishari Basu
Download or read book Preferential Oxidation of Carbon Monoxide Over Heat Treated Swellable Organically Modified Silica Supported Cobalt Oxide Catalyst written by Dishari Basu and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing global spotlight on environmentally friendly processes has driven the recent progress in proton exchange membrane fuel cell (PEMFC) technology. PEMFCs require an ultra-pure hydrogen stream as the feed gas. As little as 10 ppm of carbon monoxide (CO) in this feed can poison the platinum-based catalyst which is used in the anode of PEMFCs. Thus, this hydrogen feed stream must be purified by preferential oxidation (PROX) of CO prior to its introduction to a PEMFC. Supported precious metal catalysts have been extensively studied for catalyzing the CO PROX reaction. However, due to their lack of abundance and high costs, relatively inexpensive transition metal oxide based catalysts are promising alternatives. In this category, cobalt based catalysts have shown the most favorable results for catalyzing CO PROX. However, moisture present in the hydrogen feed has been found to considerably decrease PROX performance with time over Co based catalysts. Therefore, the synthesis of an inexpensive, water resistant Co based catalyst is required. Moisture causes decrease in PROX activity by plugging the Co3+ active sites and forming inactive complexes. To protect these active sites from H2O, a novel hydrophobic material, known as swellable organically-modified silica (SOMS) was used as the support material. However, the small pore diameter of SOMS did not allow the reactants to contact the active sites situated within its matrix. Therefore, SOMS was heat treated to tune its properties such as pore size and degree of hydrophobicity for application to this reaction. This heat treated SOMS (HSOMS) was then used to support the active Co3O4 nanoparticles. Dry and wet feed reactions were performed in a fixed bed reactor to obtain activity parameters such as CO conversion and selectivity. The effect of promotion and varying synthesis techniques was studied to synthesize a catalyst with high activity in the dry feed. The performance of the most water tolerant catalyst among the various HSOMS supported catalysts was compared to that of silica supported Co3O4. Detailed textural and surface characterization tests such as N2 physisorption, XRD, XPS and TPR were performed to understand the support morphology, phase identification of cobalt oxide, oxidation state of cobalt on the surface and reducibility of the catalyst respectively. Modifying the conventional synthesis procedure and tuning the properties of SOMS resulted in the synthesis of a more water resistant, active and stable supported Co3O4 catalyst.
Book Synopsis Recent Advances in Cobalt and Related Catalysts by : John Vakros
Download or read book Recent Advances in Cobalt and Related Catalysts written by John Vakros and published by . This book was released on 2021 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, cobalt and related catalysts are very attractive as they provide many advantages, such as low cost and high activity, in a variety of applications. Cobalt catalysts are among the most active catalysts for Fischer-Tropsch synthesis and they promote the catalytic activity of the hydrodesulfurization catalysts. They also found other significant applications in environmental protection such as oxidation of volatile organic compounds, VOC, persulfate activator, ammonia synthesis, electrocatalysis and many more. Cobalt catalysts are active, stable and exhibit significant oxidation-reduction activity, as the Co can be found either as Co(II) or Co(III). Additionally, many molecules can interact with the cobalt supported phase by co-ordination due to partially filled d-orbital. Co-catalysts can be supported in almost all the inorganic supports such as alumina, titania, zeolites, etc. The cobalt oxide phase can be stabilized on the surface of the support due to variable interactions between the support and cobalt phase. These interactions are crucial for catalytic activity and can be regulated by proper selection of the preparation parameters such as the type of support, the Co loading, impregnation method and thermal conditions.This Special Issue aims to cover recent progress and advances in the field of cobalt and related catalysts.
Book Synopsis Synthesis, Physicochemical Characterization, and Catalytic Evaluation of Three-dimensionally Ordered Macroporous Metal Oxide Catalysts and Photocatalysts by : Mohammed Abdulmajeed Al-Daous
Download or read book Synthesis, Physicochemical Characterization, and Catalytic Evaluation of Three-dimensionally Ordered Macroporous Metal Oxide Catalysts and Photocatalysts written by Mohammed Abdulmajeed Al-Daous and published by . This book was released on 2003 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Catalysis by Materials with Well-Defined Structures by : Zili Wu
Download or read book Catalysis by Materials with Well-Defined Structures written by Zili Wu and published by Academic Press. This book was released on 2015-03-26 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalysis by Materials with Well-Defined Structures examines the latest developments in the use of model systems in fundamental catalytic science. A team of prominent experts provides authoritative, first-hand information, helping readers better understand heterogeneous catalysis by utilizing model catalysts based on uniformly nanostructured materials. The text addresses topics and issues related to material synthesis, characterization, catalytic reactions, surface chemistry, mechanism, and theoretical modeling, and features a comprehensive review of recent advances in catalytic studies on nanomaterials with well-defined structures, including nanoshaped metals and metal oxides, nanoclusters, and single sites in the areas of heterogeneous thermal catalysis, photocatalysis, and electrocatalysis. Users will find this book to be an invaluable, authoritative source of information for both the surface scientist and the catalysis practitioner Outlines the importance of nanomaterials and their potential as catalysts Provides detailed information on synthesis and characterization of nanomaterials with well-defined structures, relating surface activity to catalytic activity Details how to establish the structure-catalysis relationship and how to reveal the surface chemistry and surface structure of catalysts Offers examples on various in situ characterization instrumental techniques Includes in-depth theoretical modeling utilizing advanced Density Functional Theory (DFT) methods
Book Synopsis Plasma Catalysis by : Annemie Bogaerts
Download or read book Plasma Catalysis written by Annemie Bogaerts and published by MDPI. This book was released on 2019-04-02 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma catalysis is gaining increasing interest for various gas conversion applications, such as CO2 conversion into value-added chemicals and fuels, N2 fixation for the synthesis of NH3 or NOx, methane conversion into higher hydrocarbons or oxygenates. It is also widely used for air pollution control (e.g., VOC remediation). Plasma catalysis allows thermodynamically difficult reactions to proceed at ambient pressure and temperature, due to activation of the gas molecules by energetic electrons created in the plasma. However, plasma is very reactive but not selective, and thus a catalyst is needed to improve the selectivity. In spite of the growing interest in plasma catalysis, the underlying mechanisms of the (possible) synergy between plasma and catalyst are not yet fully understood. Indeed, plasma catalysis is quite complicated, as the plasma will affect the catalyst and vice versa. Moreover, due to the reactive plasma environment, the most suitable catalysts will probably be different from thermal catalysts. More research is needed to better understand the plasma–catalyst interactions, in order to further improve the applications.
Book Synopsis Synthesis and Kinetic Study of CeO2 and SiO2 Supported CuO Catalysts for CO Oxidation by : Shaikh Tofazzel Hossain
Download or read book Synthesis and Kinetic Study of CeO2 and SiO2 Supported CuO Catalysts for CO Oxidation written by Shaikh Tofazzel Hossain and published by . This book was released on 2018 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape- and size-controlled CeO2 and SiO2 have been used in many catalysis applications. This research focused on the low-temperature CO oxidation for the automotive exhaust system. After starting a car, it needs to increase the temperature of catalytic converter to achieve full CO conversion. Toxic gas from the car pollutes the environment till the car reaches the required temperature. Thus, the preparation of efficient catalyst is much needed to lower the CO conversion temperature. This work especially focused on the correlation of the effect of catalyst supports' kind and morphology with their catalytic activity. Copper nitrate and copper carbonate precursors for wet impregnation method and copper nitrate for thermal decomposition method have been used to impregnate CuO onto hydrothermally prepared CeO2 nanorods. Several characterization techniques, such as X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM) and hydrogen temperature programmed reduction (H2-TPR) have confirmed the presence of three different copper species interacting with CeO2 nanorods while forming oxygen vacancies in CeO2 lattice by compensating the charges between copper and cerium. Cu-O-Ce solid solutions and CuO impregnated on CeO2 nanorods catalysts (CuO/CeO2) with various compositions have been prepared using thermal decomposition and hydrothermal methods, to understand the distribution effect of copper species on low temperature CO oxidation. A series of temperature programmed reduction-temperature programmed oxidation (TPR-TPO) thermal cycling studies have been conducted to understand the interactions between three assigned copper species with CeO2 support and the corresponding catalytic performance of the catalysts. The effect of support reducibility and reduction treatment has been studied in SiO2 nanospheres and CeO2 nanorods supported CuO[subscript x] catalysts on CO oxidation. CuO nanoparticles have been impregnated on SiO2 nanospheres and CeO2 nanorods using thermal decomposition method and then the samples have been oxidized in air at different temperatures (400-600 °C). The sample oxidized at 400 °C has also been further reduced under hydrogen atmosphere to compare the effect of thermal treatment (oxidation vs. reduction treatments) on the catalytic activity. In comparison to SiO2 nanospheres supported CuO[subscript x] catalysts, both CuO/CeO2 and reduced CuO[subscript x]/CeO2 catalysts exhibited superior catalytic performance in terms of CO conversion and low-temperature hydrogen consumption. The enhanced activity of CeO2 nanorods supported CuO[subscript x] catalysts has been correlated strongly to the surface defects on CeO2 nanorods and interfacial structures. In addition, in a novel design of co-supported scaffold structure catalyst, CeO2 nanorods and SiO2 nanospheres have been mixed in various ratios and 10 wt% CuO nanoparticles have been impregnated onto CeO2-SiO2 composite support using thermal decomposition method. Agglomeration of CeO2 nanorods have been stopped by introducing SiO2 nanospheres in the catalyst system, and this design can increase the chance to expose more CeO2 surface to CuO nanoparticles in order to form higher amount of surface defects (incorporation of Cu ions and oxygen vacancies) and lead to higher synergistic interaction between CuO and CeO2. H2 TPR and CO oxidation experiments suggested an enhanced low-temperature catalytic performance for 1:1 ratio mixture of CeO2 and SiO2 due to a strong interfacial interaction among SiO2-CeO2-CuO. For kinetic study, 5%CO-95%He and O2 gases have been used to reduce and oxidize CuO/CeO2 catalyst respectively at a constant temperature of 400 °C (isothermal process). Mathematical formulas for power law, diffusion, nucleation and contraction models have been used to compare with the experimental data collected during the reduction and oxidation process of the catalyst to determine the best fitted reaction mechanism.
Book Synopsis Mechanochemically Synthesized Cobalt Oxide-based Particles for the Reduction of Nitrophenols and Impacting Factors to Its Mechanism by : Lorianne Rebecca Shultz
Download or read book Mechanochemically Synthesized Cobalt Oxide-based Particles for the Reduction of Nitrophenols and Impacting Factors to Its Mechanism written by Lorianne Rebecca Shultz and published by . This book was released on 2019 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanochemically synthesized cobalt oxide-based particles are employed for the catalytic reduction of 4-nitrophenol (4NP), a toxic water contaminant. This reduction produces 4-aminophenol (4AP), a less toxic, pharmaceutical precursor for drugs such as paracetamol. The indicated reduction has been completed previously using noble metals and/or catalysts requiring extensive solvent use, and time as part of their preparation. The cost and synthesis of these noble metal catalysts hinders the sustainable broad scale application as an environmental remediation solution. The catalyst synthesis explored in this study utilizes the green chemistry technique of vibratory ball-milling and annealing cobalt oxide-based particles at different temperatures, producing unique agglomerates with differing surface structure and catalytic properties. Additional investigation into the mechanism through temperature, pH, and change in pressure over the reaction is completed. Further analysis shows that these catalysts are efficient for the reduction of 4-amino-3-nitrophenol and 2-amino-5-nitrophenol with unique catalytic rates. Finally, it is found that the application of this reduction in a flow process has potential for use on a broader scale.
Book Synopsis Effect of Cobalt and Zinc Precursor Loading on the Catalyst Activity of Fischertropsch Synthesis by : Nadia Aida Che Mustapa
Download or read book Effect of Cobalt and Zinc Precursor Loading on the Catalyst Activity of Fischertropsch Synthesis written by Nadia Aida Che Mustapa and published by . This book was released on 2012 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five samples of Co-Zn/SBA-15 catalysts were prepared using wet impregnation method with different composition of cobalt loading (5, 10 and 15 wt % Co) and zinc loading (5, 10 and 15 wt % Zn) and were investigated with respect to physical and chemical properties as well influence on activity and selectivity for conversion of H2/CO2 synthesis gas. The catalysts were tested by using Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), N2 Adsorption Analysis (BET) and Thermogravimetric Analyzer (TGA). The feed gas of CO2 instead of CO also had been considered that contributed to product selectivity since cobalt catalyst do not exhibit significantly in Water Gas Shift (WGS) activity and CO2 neither formed nor produced during Fischer Tropsch (FT) synthesis with cobalt catalyst and H2/CO. An investigation of catalytic CO2 hydrogenation into high quality fuels and valuable hydrocarbons was carried out in a glass borosilicate reactor. The operating condition for catalytic testing is at 220 °C and 1 bar using H2/CO2 feed ratios of 3:1. Selectivity of products was depending upon the amount of metal loading constituent as well as the syngas mixture that used. It was found that higher metal loading with optimized promoter loading was the best catalyst for Fischer Tropsch synthesis. It is experimentally found that from the result of gas chromatograph, the conversion of CO2 and product selectivities were calculated. The most efficient catalyst for Ficher Tropsch synthesis is 15% Co/10% Zn-SBA-15. This result was proven by the characteristic of catalyst which is the existance functional groups of cobalt oxides, Si-O-Si, Si-CH3, zinc oxide, OH band, Si-C, and others, higher intensity that indicates higher cobalt dispersion, possess large surface area as well as pore size, small weight loses that indicate thermal stability and having large number of catalyst particles attaching closely with one another that make it more effective during FT process.
Book Synopsis Iron and Cobalt Catalysts by : Wilson D Shafer
Download or read book Iron and Cobalt Catalysts written by Wilson D Shafer and published by . This book was released on 2020 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the turn of the last century when the field of catalysis was born, iron and cobalt have been key players in numerous catalysis processes. These metals, due to their ability to activate CO and CH, haev a major economic impact worldwide. Several industrial processes and synthetic routes use these metals: biomass-to-liquids (BTL), coal-to-liquids (CTL), natural gas-to-liquids (GTL), water-gas-shift, alcohol synthesis, alcohol steam reforming, polymerization processes, cross-coupling reactions, and photocatalyst activated reactions. A vast number of materials are produced from these processes, including oil, lubricants, waxes, diesel and jet fuels, hydrogen (e.g., fuel cell applications), gasoline, rubbers, plastics, alcohols, pharmaceuticals, agrochemicals, feed-stock chemicals, and other alternative materials. However, given the true complexities of the variables involved in these processes, many key mechanistic issues are still not fully defined or understood. This Special Issue of Catalysis will be a collaborative effort to combine current catalysis research on these metals from experimental and theoretical perspectives on both heterogeneous and homogeneous catalysts. We welcome contributions from the catalysis community on catalyst characterization, kinetics, reaction mechanism, reactor development, theoretical modeling, and surface science.
