Готові списки джерел за темами / Mixed Oxide Catalyst

Добірка наукової літератури з теми "Mixed Oxide Catalyst"

Автор: Grafiati

Опубліковано: 14 березня 2023

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Статті в журналах з теми "Mixed Oxide Catalyst"

Mazaheri, Hoora, Hwai Chyuan Ong, Zeynab Amini, Haji Hassan Masjuki, M. Mofijur, Chia Hung Su, Irfan Anjum Badruddin, and T. M. Yunus Khan. "An Overview of Biodiesel Production via Calcium Oxide Based Catalysts: Current State and Perspective." Energies 14, no. 13 (July 1, 2021): 3950. http://dx.doi.org/10.3390/en14133950.

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Biodiesel is a clean, renewable, liquid fuel that can be used in existing diesel engines without modification as pure or blend. Transesterification (the primary process for biodiesel generation) via heterogeneous catalysis using low-cost waste feedstocks for catalyst synthesis improves the economics of biodiesel production. Heterogeneous catalysts are preferred for the industrial generation of biodiesel due to their robustness and low costs due to the easy separation and relatively higher reusability. Calcium oxides found in abundance in nature, e.g., in seashells and eggshells, are promising candidates for the synthesis of heterogeneous catalysts. However, process improvements are required to design productive calcium oxide-based catalysts at an industrial scale. The current work presents an overview of the biodiesel production advancements using calcium oxide-based catalysts (e.g., pure, supported, and mixed with metal oxides). The review discusses different factors involved in the synthesis of calcium oxide-based catalysts, and the effect of reaction parameters on the biodiesel yield of calcium oxide-based catalysis are studied. Further, the common reactor designs used for the heterogeneous catalysis using calcium oxide-based catalysts are explained. Moreover, the catalytic activity mechanism, challenges and prospects of the application of calcium oxide-based catalysts in biodiesel generation are discussed. The study of calcium oxide-based catalyst should continue to be evaluated for the potential of their application in the commercial sector as they remain the pivotal goal of these studies.

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Mohd Sidek, Haslinda, Irmawati Ramli, Norhazlin Zainuddin, Hossein Abbastabar Ahangar, and Yun Hin Taufiq-Yap. "Physicochemical Properties of MoVTeNb Mixed Oxide Catalysts Synthesized using Different Vanadium Sources." Sains Malaysiana 50, no. 8 (August 31, 2021): 2395–405. http://dx.doi.org/10.17576/jsm-2021-5008-21.

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The use of different vanadium sources in the synthesis of multi-metal MoVTeNb oxide catalysts has been investigated for their effect on the physicochemical properties of catalysts. Metal oxides were synthesized by slurry method assisted with a microwave irradiation. Vanadium pentoxide (V2O5), vanadyl sulphate (VOSO4) and ammonium metavanadate (NH4VO3) were used as the vanadium sources, respectively. X-ray diffraction (XRD) pattern showed the existence of orthorhombic (M1) phases in all catalysts. The catalyst prepared using V2O5 produced the highest formation of the phase. This was further supported by Inductive Couple Plasma-Atomic Emission Spectroscopy (ICP-AES), which showed that the V2O5 catalyst has the highest V: Mo ratio, mainly responsible for the high catalytic activity. Temperature Programmed Reduction in Hydrogen (H2-TPR) showed better reducibility for the catalyst when compared to the others. Temperature Programmed Reaction (TPRn) confirmed that the oxidants active for propane conversion into acrylic acid were originated from the lattice of the catalyst.

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Pacultová, Bílková, Klegova, Karásková, Fridrichová, Jirátová, Kiška, et al. "Co-Mn-Al Mixed Oxides Promoted by K for Direct NO Decomposition: Effect of Preparation Parameters." Catalysts 9, no. 7 (July 9, 2019): 593. http://dx.doi.org/10.3390/catal9070593.

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Fundamental research on direct NO decomposition is still needed for the design of a sufficiently active, stable and selective catalyst. Co-based mixed oxides promoted by alkali metals are promising catalysts for direct NO decomposition, but which parameters play the key role in NO decomposition over mixed oxide catalysts? How do applied preparation conditions affect the obtained catalyst’s properties?

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Kustov, Alexander L., Andrey L. Tarasov, Olga P. Tkachenko, Igor V. Mishin, Gennady I. Kapustin, and Leonid M. Kustov. "Ethanol to Acetaldehyde Conversion under Thermal and Microwave Heating of ZnO-CuO-SiO2 Modified with WC Nanoparticles." Molecules 26, no. 7 (March 31, 2021): 1955. http://dx.doi.org/10.3390/molecules26071955.

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The nonoxidative conversion of ethanol to acetaldehyde under thermal and microwave heating was studied on mixed oxide ZnO-CuO-SiO2 catalysts modified with additives of tungsten carbide nanoparticles. The results revealed that the WC-modified catalyst exhibited superior activity and selectivity under microwave heating conditions. It is assumed that when microwave heating is used, hot zones can appear at the contact points of WC nanoparticles and active centers of the mixed oxide ZnO-CuO-SiO2 catalyst, which intensively absorb microwave energy, allowing the more efficient formation of acetaldehyde at moderate temperatures. Thermodynamic calculations of equilibrium concentrations of reagents and products allowed us to identify the optimal conditions for effective acetaldehyde production. The initial catalyst and the catalyst prepared by the coprecipitation of the oxides with the addition of WC were characterized by physicochemical methods (TPR-H2, XRD, DRIFTS of adsorbed CO). The active centers of the oxide catalyst can be Cu+ cations.

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MIKHAILOVSKAYA, T. P., R. KURMAKYZY, D. K. TOLEMISOVA, and K. A. KADIRBEKOV. "OXIDATIVE AMMONOLYSIS OF 4-METHYLPYRIDINE ON OXIDE VANADIUM-TITANIUM-ZIRCONIUM CATALYST MODIFIED BY TIN AND TUNGSTEN OXIDES." Chemical Journal of Kazakhstan 73, no. 1 (March 14, 2021): 196–203. http://dx.doi.org/10.51580/2021-1/2710-1185.21.

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Catalysts based on vanadium pentoxide modified by Ti, Sn, Zr and W oxides were tested in the oxidative ammonolysis of 4-methylpyridine. The role of the main process parameters such as temperature, the ratio of the initial components in the conversion of the methyl group to the nitrile one, and the optimal conditions for the oxidative ammonolysis of 4-methylpyridine were determined. It is determined that the V-Ti-Zr-O-catalyst and the sample containing 9% of tungsten oxide are superior in catalytic activity to the V-Ti-Zr-Sn-O contact. Conditions that ensure a high selectivity for the formation of 4-cyanopyridine were found. The highest yield of the target product (85-86%) was obtained on V-Ti-Zr-W-O at 270 °C, and the yield of 4-cyanopyridine was 87.5% at 310° C on the V-Ti-Zr-Sn-O catalyst. The phase composition and structural changes occurring in modified vanadium oxide catalysts have been studied. It is determined that mixed V-Ti-Zr-Sn-O and V-Ti-Zr-W-O catalysts contain ZrV2O7, the monoclinic modification of ZrO2 (baddeleyite), TiO2 (anatase), SnO2, WO3, and V2O5. In catalysts, it can exist in small amounts as a separate VO2 phase. The V-Ti-Zr-W-O catalyst showed the best catalytic properties. It has highactivity and selectivity towards 4-cyanopyridine.

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Ali, Syed Danish, Isma Noreen Javed, Usman Ali Rana, Muhammad Faizan Nazar, Waqas Ahmed, Asifa Junaid, Mahmood Pasha, Rumana Nazir, and Rizwana Nazir. "Novel SrO-CaO Mixed Metal Oxides Catalyst for Ultrasonic-Assisted Transesterification of Jatropha Oil into Biodiesel." Australian Journal of Chemistry 70, no. 3 (2017): 258. http://dx.doi.org/10.1071/ch16236.

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The transesterification of edible and non-edible oils to produce biodiesel is traditionally carried out using homogeneous catalysts (such as NaOH, KOH, and H2SO4). However, these homogenous catalysts often suffer from multiple drawbacks including their corrosive nature and solubility in the reaction mixture, and high costs associated with their recovery. Recent studies have shown that heterogeneous catalysts based on mixed metal oxides have the potential to address the issues associated with conventional homogeneous catalysts, thereby emerging as an efficient class of catalyst materials for biodiesel production. In this study, we describe a heterogeneous strontium oxide/calcium oxide (SrO-CaO) mixed metal oxides catalyst, which displays remarkable efficiency towards the ultrasonic-assisted transesterification of Jatropha oil into biodiesel. The SrO-CaO heterogeneous catalyst was prepared by the wet impregnation method, and the structural morphology of the as-synthesized catalyst was revealed by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and nitrogen sorption technique coupled with the Brunauer–Emmett–Teller and Barrett–Joyner–Halenda methods. The X-ray diffraction analysis confirmed the cubic structure of the SrO-CaO catalyst. The catalytic activity of this newly developed catalyst showed a high percentage conversion of triglyceride into the corresponding fatty acid methyl esters (98.19 %) as confirmed by 1H NMR spectroscopy. The chemical composition of the prepared biodiesel by this ultrasonic-assisted transesterification process was determined by the gas chromatography–mass spectrometry. Five major fatty acid methyl esters were identified, of which 9-octadecenoic acid methyl ester was obtained with the highest percentage ~38.22 %. Hence, the study reveals that the SrO-CaO catalyst exhibits high efficiency towards converting Jatropha oil into biodiesel by ultrasonic-assisted transesterification.

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Li, Xue, Zi Yuan Zhou, Li Wei Zhu, and Jian Xin Jiang. "Characterization of Lanthanum Nitrate Modified CaMgZn Mixed Oxide Catalysts for Synthesis of Biodiesel." Advanced Materials Research 581-582 (October 2012): 283–86. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.283.

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CaMgZn mixed oxide (CMZ) catalysts were modified by addition of lanthanum nitrate, and the use of modified catalysts (CMZL) for biodiesel synthesis were investigated. The conditions of biodiesel production with modified catalysts were optimized. Using optimized conditions, including lanthanum nitrate addition of 3wt.%, catalyst amount of 5wt.%, reaction temperature of 50°C, methanol to oil molar ratio of 15:1 and reaction time of 1h, the glycerol yield of 86.80% catalyzed by CMZL could be attained, which was higher compared with the CMZ catalyzed process of 82.94%. Brunauer–Emmett–Teller (BET), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) were used to compare the modified CMZL catalyst with the CMZ bare catalyst. The results indicated that the lanthanum modified catalysts (CMZL) have excellent surface property. The modified catalysts could be suitable for commercial application.

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Al-Aani, Hussein Mahdi S., Mihaela M. Trandafir, Ioana Fechete, Lucia N. Leonat, Mihaela Badea, Cătălin Negrilă, Ionel Popescu, Mihaela Florea, and Ioan-Cezar Marcu. "Highly Active Transition Metal-Promoted CuCeMgAlO Mixed Oxide Catalysts Obtained from Multicationic LDH Precursors for the Total Oxidation of Methane." Catalysts 10, no. 6 (June 1, 2020): 613. http://dx.doi.org/10.3390/catal10060613.

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To improve the catalytic performance of an active layered double hydroxide (LDH)-derived CuCeMgAlO mixed oxide catalyst in the total oxidation of methane, it was promoted with different transition-metal cations. Thus, two series of multicationic mixed oxides were prepared by the thermal decomposition at 750 °C of their corresponding LDH precursors synthesized by coprecipitation at constant pH of 10 under ambient atmosphere. The first series of catalysts consisted of four M(3)CuCeMgAlO mixed oxides containing 3 at.% M (M = Mn, Fe, Co, Ni), 15 at.% Cu, 10 at.% Ce (at.% with respect to cations), and with Mg/Al atomic ratio fixed to 3. The second series consisted of four Co(x)CuCeMgAlO mixed oxides with x = 1, 3, 6, and 9 at.% Co, while keeping constant the Cu and Ce contents and the Mg/Al atomic ratio. All the mixed oxides were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) coupled with X-ray energy dispersion analysis (EDX), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption at −196 °C, temperature-programmed reduction under hydrogen (H2-TPR), and diffuse reflectance UV-VIS spectroscopy (DR UV-VIS), while thermogravimetric and differential thermal analyses (TG-DTG-DTA) together with XRD were used for the LDH precursors. The catalysts were evaluated in the total oxidation of methane, a test reaction for volatile organic compounds (VOC) abatement. Their catalytic performance was explained in correlation with their physicochemical properties and was compared with that of a reference Pd/Al2O3 catalyst. Among the mixed oxides studied, Co(3)CuCeMgAlO was found to be the most active catalyst, with a temperature corresponding to 50% methane conversion (T50) of 438 °C, which was only 19 °C higher than that of a reference Pd/Al2O3 catalyst. On the other hand, this T50 value was ca. 25 °C lower than that observed for the unpromoted CuCeMgAlO system, accounting for the improved performance of the Co-promoted catalyst, which also showed a good stability on stream.

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Liu, Fang, Li Yang, Jie Cheng, Xin Wu, Wenbin Quan, and Kozo Saito. "Low Temperature deNOx Catalytic Activity with C2H4 as a Reductant Using Mixed Metal Fe-Mn Oxides Supported on Activated Carbon." Energies 12, no. 22 (November 14, 2019): 4341. http://dx.doi.org/10.3390/en12224341.

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The selective catalytic reduction of NOx (deNOx) at temperatures less than or at 200 °C was investigated while using C2H4 as the reductant and mixed oxides of Fe and Mn supported on activated carbon; their activity was compared to that of MnOx and FeOx separately supported on activated carbon. The bimetallic oxide compositions maintained high NO conversion of greater than 80–98% for periods that were three times greater than those of the supported monometallic oxides. To examine potential reasons for the significant increases in activity maintenance, and subsequent deactivation, the catalysts were examined by using bulk and surface sensitive analytical techniques before and after catalyst testing. No significant changes in Brunauer-Emmett-Teller (BET) surface areas or porosities were observed between freshly-prepared and tested catalysts whereas segregation of FeOx and MnOx species was readily observed in the mono-oxide catalysts after reaction testing that was not detected in the mixed oxide catalysts. Furthermore, x-ray diffraction and Raman spectroscopy data detected cubic Fe3Mn3O8 in both the freshly-prepared and reaction-tested mixed oxide catalysts that were more crystalline after testing. The presence of this compound, which is known to stabilize multivalent Fe species and to enhance oxygen transfer reactions, may be the reason for the high and relatively stable NO conversion activity, and its increased crystallinity during longer-term testing may also decrease surface availability of the active sites responsible for NO conversion. These results point to a potential of further enhancing catalyst stability and activity for low temperature deNOx that is applicable to advanced SCR processing with lower costs and less deleterious side effects to processing equipment.

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Kis, Erne, Matilda Lazic, and Goran Boskovic. "Catalyst component interactions in nickel/alumina catalyst." Acta Periodica Technologica, no. 38 (2007): 61–68. http://dx.doi.org/10.2298/apt0738061k.

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The influence of nickel loading (5; 10; 20 wt% Ni), temperature of heat treatment (400; 700; 1100?C) and way of catalyst preparation on the catalyst component interactions (CCI) in the impregnated, mechanical powder mixed and co-precipitated catalyst was investigated. For sample characterization, low temperature nitrogen adsorption (LTNA) and X-ray diffraction (XRD) were applied. Significant differences were revealed, concerning CCI in dependence of nickel loading, temperature of heat treatment and way of catalyst preparation. The obtained results show that the support metal oxide interactions (SMI) in impregnated and co-precipitated catalysts are more intensive than in the mechanical powder mixed catalyst. The degree and intensity of CCI is expressed by the ratio of real and theoretical surface area of the catalyst. This ratio can be used for a quantitative estimation of CCI and it is generally applicable to all types of heterogeneous catalysts.

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Більше джерел

Дисертації з теми "Mixed Oxide Catalyst"

Meshesha, Beteley Tekola. "Hydrodechlorination of chlorinated organic wastes over pd supported mixed oxide catalysts." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/37352.

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Environmental pollution by polychlorinated chlorinated organic wastes is of great concern. Catalytic hydrodechlorination is considered clean and efficient methodology for safe disposal of chlorinated organic wastes. This work aims at studying the catalytic hydrodechlorination reaction for the removal of environmentally polluting chlorinated organic wastes: 1,2,4-trichlorobenzene (1,2,4-TCB) and Trichloroethylene (TCE). The research has focused on evaluation of the activity, selectivity and stability of newly synthesized Pd based catalysts for hydrodechlorination of 1,2,4-trichlorobenzene and trichloroethylene. The first part, related to the HDC of 1,2,4-TCB, is to obtain active and stable catalyst for the hydrodechlorination of C-Cl bond of aromatic compounds to non chlorinated organic aromatic compound (benzene). While the second part aims at obtaining catalysts that allow high selectivity to ethylene formation during the HDC Trichloroethylene. Pd based hydrotalcite derived mixed oxides with different surface property were explored as catalysts for hydrodechlorination reaction. In addition, bimetallic and monometallic heterogeneous catalytic systems were investigated for selective hydrodechlorination reaction. Detailed characterization of the active centers of the newly synthesized catalysts by different techniques was achieved. This work presents original ideas, which could find a practical application, for the treatment of organo-halogenated pollutants.
La contaminación ambiental mediante compuestos policlorados aromáticos y alifáticos es de gran preocupación. La reacción de hidrodecloración catalítica selectiva (HDC) se presenta como una nueva tecnología eficaz para una eliminación segura de estos tipos de compuestos orgánicos clorados. Es por ello, que este trabajo de investigación se ha enfocado en el estudio de nuevos catalizadores activos, selectivos y estables en diferentes reacciones de hidrodecloración de dos familias de compuestos orgánicos clorados: 1,2,4-triclorobenceno (1,2,4-TCB-compuestos aromáticos clorados) y el tricloroetileno (representativo de un compuesto clorado alifático). La primera parte de la tesis relacionadas con el HDC de 1,2,4-TCB, tiene como objetivo la obtención de catalizadores activos y estables para la hidrogenación del enlace C-Cl en compuestos aromáticos y la obtención final del compuesto aromático orgánico declorado. Mientras que la segunda parte tiene por objeto la obtención de catalizadores que permitan una gran selectividad a etileno y no hacia etano (hidrogenación profunda del tricloroetileno) durante la HDC de tricloroetileno. Por otra parte se ha realizado un estudio profundo en la síntesis de estos nuevos catalizadores, así como en la caracterización de los centros activos de dichos catalizadores, para su correlación con la actividad, selectividad y estabilidad de dichos catalizadores. Presenta ideas originales, lo que podría encontrar una aplicación práctica, para el tratamiento de compuestos órgano-halogenados contaminantes.

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Romano, Esteban Javier. "A surface science approach to understanding emission control catalyst deactivation due to sulfation of ceria-zirconia mixed-metal oxides." Master's thesis, Mississippi State : Mississippi State University, 2004. http://library.msstate.edu/etd/show.asp?etd=etd-03252004-162922.

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Rico, Francés Soledad. "Pt/TixCe(1-x)O2 catalysts for PROX reaction." Doctoral thesis, Universidad de Alicante, 2015. http://hdl.handle.net/10045/50208.

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The main objective of this Thesis is the synthesis, characterization and application in the PROX reaction of several series of catalysts synthesized using different methods, in order to find efficient materials with high catalytic activity. This work has been divided in six chapters. Chapter I presents an introduction about current energy problems and hydrogen (energy carrier) as a solution, with its limitations and advances on its use: storage, transport and security. Finally, its use as a fuel in PEMFC (Proton Exchange Membrane Fuel Cells) and the advantages comparing other existent fuel cells has been discussed. A brief summary was done about the catalytic systems studied in literature for PROX reaction and their characteristics. Following, Chapter 2 describes all the characterization techniques which were used to study the properties of the synthesized supports and catalysts, together with the experimental system employed for the catalytic tests. Most of these equipments belong to SSTTI of University of Alicante or are hand-made systems in the LMA group. DRIFTs and DTP were done at TUDelft, Catalysis Engineering Section. Next chapters contain the most important results obtained during the complete research work; they have been divided in two parts. On one hand, Chapter 3 describes the synthesis of pure TiO2 using five different methods, and its use as platinum support for PROX catalysts. On the other hand, taking into account the obtained results, three synthesis methods were chosen, and the study was centered in the addition of CeO2 to TiO2. Chapter 4 discusses the TixCe(1-x)O2 series synthesized using the sol-gel method. In Chapter 5 a solvothermal procedure was employed for the synthesis of supports with similar composition and, finally, impregnation of cerium over commercial P25 titania was compared in Chapter 6. Each chapter contains a complete study of characterization of both supports and catalysts. Synthesis parameters, pretreatment and reaction conditions were also modified for the best catalyst of the three series. Analyzing the catalysts’ behavior, a reaction mechanism was proposed. Finally, general conclusions summarize the most relevant results obtained in each chapter.

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Whittle, David Mark. "The structural characterisation of mixed-oxide catalyst systems by high resolution- and scanning transmission microscopy techniques." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263767.

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Karslioglu, Osman. "Structural and chemical characterizations of Mo–Ti mixed oxide layers." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2013. http://dx.doi.org/10.18452/16767.

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In dieser Arbeit wurde ein Modell-Katalysator-Ansatz angewandt um Mischoxide mit Molybdän und Titan zu untersuchen. Die Schichten wurden auf TiO2(110) Einkristallen durch Verdampfen der Metalle in einer O2 Atmosphäre und in UHV und Nachbehandlung der Filme vorbereitet. Verschiedene Präparationen wurden in der Studie untersucht und diese werden in sechs Kategorien dargestellt. Wenn Mo und Ti in O2 gemeinsam aufgedampft wurden, wurde das meiste Mo an der Oberfläche abgeschieden mit einer nur geringen Mo-Konzentration in tieferen Schichten. Eine Mischung von Mo in TiO2 war sehr begrenzt, und die stimmt mit dem Phasendiagramm MoO2 und TiO2 überein. Mo6+ und Mo4+ sind die dominierenden Oxidationsstufen in den meisten der Schichten, wobei Mo6+ stets näher an der Oberfläche war als Mo4+. Schichten, in denen Mo vollständig in TiO2 gelöst ist, konnten durch Abscheidung von Metallen in UHV und Post-Oxidation der Filme erstellt werden. Im Inneren des TiO2 Gitters hat Mo die Oxidationsstufe 4+. Aufdampfen von Mo in O2 bei Raumtemperatur und anschließendes Tempern in UHV führte zur Bildung zweier Arten von Merkmalen in den STM-Bildern. Diese waren im UHV stabil bis mindestens 1000 K. Die Schichten mit hoher Mo-Konzentrationen erschienen uneinheitlich in den STM-Bildern aber sie zeigte das TiO2(110)-(1x1) LEED-Muster. Der Anstieg in der Mo-Konzentration führte zur Blockierung der Überbrückung Sauerstoffleerstellen (BOVs), was durch STM und Wasser-TPD nachgewiesen wurde. Die Reaktivitäten der Schichten wurden mit Methanol- und Ethanol-TPD getestet. Eine unerwartete Formaldehyd/Methanbildung bei hohen Temperaturen (~650 K) wurde bei der Methanol-TPD von reinem TiO2(110) beobachtet und mit BOVs in Verbindung gebracht. Der Anstieg der Mo-Konzentration unterdrückte diesen Effekt sowie die Ethylenbildung (~600 K) beim Durchführen von Ethanol-TPD. Sowohl in Ethanol als auch Methanol-TPD wurden neue Reaktionswege zu Ethylen und Methan-Bildung bei ~500 K beobachtet.
In this work, a model-catalyst approach has been taken to study oxide mixtures containing molybdenum and titanium. The layers were prepared on TiO2(110) single crystals by evaporating the metals in an O2 atmosphere or in UHV and post treating the deposited material. Different preparation procedures were employed in the study and these are presented in six categories. When Mo and Ti were co-deposited in O2, most of the molybdenum stayed at the surface with only a small Mo concentration in deeper layers. Mixing of Mo into TiO2 was very limited, consistent with the phase diagram of MoO2 and TiO2. Mo6+ and Mo4+ were the dominant oxidation states in most of the layers and Mo6+ was always nearer to the surface than Mo4+. Layers where Mo was completely mixed into TiO2 could be prepared by depositing metals in UHV and post-oxidizing the deposited material. Inside the TiO2 lattice, Mo had an oxidation state of 4+. Depositing Mo in O2 at room temperature and post annealing in UHV led to the formation of two types of features in the STM images. These features were stable in UHV up to at least 1000 K. The layers with high Mo concentrations appeared patchy in the STM images but they still exhibited the TiO2(110)-(1x1) LEED pattern. The increase in Mo concentration led to the blocking of the bridging oxygen vacancies (BOVs) as evidenced by STM and water TPD. The reactivities of the layers were tested by methanol and ethanol TPD. An unprecedented high temperature (~650 K) formaldehyde/methane formation channel was observed in the methanol TPD of clean TiO2(110) and was associated with BOVs. The increase in the Mo concentration led to the vanishing of this channel as well as the ethylene formation channel (~600 K) in the case of ethanol TPD. In both ethanol and methanol TPD, new reaction channels towards ethylene and methane formation at ~500 K appeared.

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Elfaki, Hind Omer Elsheikh. "Hydrogen production through sorption-enhanced steam reforming of ethanol using CaO-based sorbent mixed with iron oxide catalyst." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/31789/.

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Novel synthetic CaO-based sorbents for carbon dioxide (CO2) capture in sorption-enhanced steam reforming (SESR) were prepared by the co-precipitation method. Magnesium oxide (MgO) and cerium oxide (CeO2) were mixed with calcium oxide (CaO) in different molar percentages in order to obtain the optimum percentage, which provide high CO2 uptake capacity and cyclic stability. The TGA results for CO2 uptake, revealed that for the molar ratio of CaO, MgO and CeO2 of (6:2:1) and (4:2:1), the sorbents had CO2 capture capacity of 29 and 25 wt.%, respectively. The fresh sorbents were characterized using X-ray diﬀraction, mercury porosimetry, N2 physisorption and scanning electron microscopy. It was found that the sorbents with higher CO2 uptake capacities had relatively high porous surface structure with porosity percentage (>66%). Modelling of CO2 uptake kinetics showed that JMA (Johnson-Mehl-Avrami) fits best the first and second stages except for the molar ratio of CaO, MgO and CeO2 of (4:2:1) sample where, surface chemisorption (SC) fits the initial stage and JMA fits the second stage. While the contracting volume model (CV2/3) fits the final stages of all the studied sorbents. The stability of sorbents at high temperatures was examined over multiple cycles of carbonation/de-carbonation reactions. After 45 cycles, the sample with a molar ratio of CaO, MgO and CeO2 of (6:2:1) remained as high as 25 wt.% (0.43g CO2 /1g CaO) with only 25% decrease from its CO2 uptake capacity as a fresh sample. Therefore, the latter sample was selected to be mixed with iron oxide catalyst and used for the SESR. The study of ethanol steam reforming employing an iron oxide as a catalyst, with and without in-situ CO2 removal, has been investigated. The results confirmed that iron oxide exhibited catalytic activity for hydrogen (H2) production from ethanol steam reforming/decomposition reactions. Furthermore, the CaO-based sorbent had sucessfully decrease the amount of CO2 produced during ethanol reforming reaction up to 70 min of reaction time. Ethanol reformation with in-situ CO2 removal was investigated at 550-700 °C. The maximum H2 yield achieved was 3.5 mol (H2) /mol (EtOH) at 600°C. GC results revealed that there was no evidence of CO and C across the studied temperature range. The results showed an enhancement in reaction reactivity by increasing the gas hourly space velocities (GHSVs). The amount of H2 produced remained stable within 10 cycles, which is equivalent to 30 hours of reaction time.

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Min, Byoung Koun. "Scanning tunneling microscopic studies of SiO2 thin film supported metal nano-clusters." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/2737.

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This dissertation is focused on understanding heterogeneous metal catalysts supported on oxides using a model catalyst system of SiO2 thin film supported metal nano-clusters. The primary technique applied to this study is scanning tunneling microscopy (STM). The most important constituent of this model catalyst system is the SiO2 thin film, as it must be thin and homogeneous enough to apply electron or ion based surface science techniques as well as STM. Ultra-thin SiO2 films were successfully synthesized on a Mo(112) single crystal. The electronic and geometric structure of the SiO2 thin film was investigated by STM combined with LEED, Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS). The relationship between defects on the SiO2 thin film and the nucleation and growth of metal nano-clusters was also investigated. By monitoring morphology changes during thermal annealing, it was found that the metal-support interaction is strongly dependent on the type of metal as well as on the defect density of the SiO2 thin film. Especially, it was found that oxygen vacancies and Si impurities play an important role in the formation of Pd-silicide. By substituting Ti atoms into the SiO2 thin film network, an atomically mixed TiO2-SiO2 thin film was synthesized. Furthermore, these Ti atoms play a role as heterogeneous defects, resulting in the creation of nucleation sites for Au nano-clusters. A marked increase in Au cluster density due to Ti defects was observed in STM. A TiO2-SiO2 thin film consisting of atomic Ti as well as TiOx islands was also synthesized by using higher amounts of Ti (17 %). More importantly, this oxide surface was found to have sinter resistant properties for Au nano-clusters, which are desirable in order to make highly active Au nano-clusters more stable under reaction conditions.

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Beppu, Kosuke. "Studies on Sr-Fe Mixed Oxides for Purifying Automotive Exhaust Gas." Kyoto University, 2018. http://hdl.handle.net/2433/232055.

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Beckler, Robert Kendall. "Polynuclear metal complexes as model mixed oxide catalysts." Diss., Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/11897.

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Zheng, Zhanfeng. "Synthesis and modifications of metal oxide nanostructures and their applications." Thesis, Queensland University of Technology, 2009. https://eprints.qut.edu.au/31728/1/Zhanfeng_Zheng_Thesis.pdf.

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Transition metal oxides are functional materials that have advanced applications in many areas, because of their diverse properties (optical, electrical, magnetic, etc.), hardness, thermal stability and chemical resistance. Novel applications of the nanostructures of these oxides are attracting significant interest as new synthesis methods are developed and new structures are reported. Hydrothermal synthesis is an effective process to prepare various delicate structures of metal oxides on the scales from a few to tens of nanometres, specifically, the highly dispersed intermediate structures which are hardly obtained through pyro-synthesis. In this thesis, a range of new metal oxide (stable and metastable titanate, niobate) nanostructures, namely nanotubes and nanofibres, were synthesised via a hydrothermal process. Further structure modifications were conducted and potential applications in catalysis, photocatalysis, adsorption and construction of ceramic membrane were studied. The morphology evolution during the hydrothermal reaction between Nb2O5 particles and concentrated NaOH was monitored. The study demonstrates that by optimising the reaction parameters (temperature, amount of reactants), one can obtain a variety of nanostructured solids, from intermediate phases niobate bars and fibres to the stable phase cubes. Trititanate (Na2Ti3O7) nanofibres and nanotubes were obtained by the hydrothermal reaction between TiO2 powders or a titanium compound (e.g. TiOSO4·xH2O) and concentrated NaOH solution by controlling the reaction temperature and NaOH concentration. The trititanate possesses a layered structure, and the Na ions that exist between the negative charged titanate layers are exchangeable with other metal ions or H+ ions. The ion-exchange has crucial influence on the phase transition of the exchanged products. The exchange of the sodium ions in the titanate with H+ ions yields protonated titanate (H-titanate) and subsequent phase transformation of the H-titanate enable various TiO2 structures with retained morphology. H-titanate, either nanofibres or tubes, can be converted to pure TiO2(B), pure anatase, mixed TiO2(B) and anatase phases by controlled calcination and by a two-step process of acid-treatment and subsequent calcination. While the controlled calcination of the sodium titanate yield new titanate structures (metastable titanate with formula Na1.5H0.5Ti3O7, with retained fibril morphology) that can be used for removal of radioactive ions and heavy metal ions from water. The structures and morphologies of the metal oxides were characterised by advanced techniques. Titania nanofibres of mixed anatase and TiO2(B) phases, pure anatase and pure TiO2(B) were obtained by calcining H-titanate nanofibres at different temperatures between 300 and 700 °C. The fibril morphology was retained after calcination, which is suitable for transmission electron microscopy (TEM) analysis. It has been found by TEM analysis that in mixed-phase structure the interfaces between anatase and TiO2(B) phases are not random contacts between the engaged crystals of the two phases, but form from the well matched lattice planes of the two phases. For instance, (101) planes in anatase and (101) planes of TiO2(B) are similar in d spaces (~0.18 nm), and they join together to form a stable interface. The interfaces between the two phases act as an one-way valve that permit the transfer of photogenerated charge from anatase to TiO2(B). This reduces the recombination of photogenerated electrons and holes in anatase, enhancing the activity for photocatalytic oxidation. Therefore, the mixed-phase nanofibres exhibited higher photocatalytic activity for degradation of sulforhodamine B (SRB) dye under ultraviolet (UV) light than the nanofibres of either pure phase alone, or the mechanical mixtures (which have no interfaces) of the two pure phase nanofibres with a similar phase composition. This verifies the theory that the difference between the conduction band edges of the two phases may result in charge transfer from one phase to the other, which results in effectively the photogenerated charge separation and thus facilitates the redox reaction involving these charges. Such an interface structure facilitates charge transfer crossing the interfaces. The knowledge acquired in this study is important not only for design of efficient TiO2 photocatalysts but also for understanding the photocatalysis process. Moreover, the fibril titania photocatalysts are of great advantage when they are separated from a liquid for reuse by filtration, sedimentation, or centrifugation, compared to nanoparticles of the same scale. The surface structure of TiO2 also plays a significant role in catalysis and photocatalysis. Four types of large surface area TiO2 nanotubes with different phase compositions (labelled as NTA, NTBA, NTMA and NTM) were synthesised from calcination and acid treatment of the H-titanate nanotubes. Using the in situ FTIR emission spectrescopy (IES), desorption and re-adsorption process of surface OH-groups on oxide surface can be trailed. In this work, the surface OH-group regeneration ability of the TiO2 nanotubes was investigated. The ability of the four samples distinctively different, having the order: NTA > NTBA > NTMA > NTM. The same order was observed for the catalytic when the samples served as photocatalysts for the decomposition of synthetic dye SRB under UV light, as the supports of gold (Au) catalysts (where gold particles were loaded by a colloid-based method) for photodecomposition of formaldehyde under visible light and for catalytic oxidation of CO at low temperatures. Therefore, the ability of TiO2 nanotubes to generate surface OH-groups is an indicator of the catalytic activity. The reason behind the correlation is that the oxygen vacancies at bridging O2- sites of TiO2 surface can generate surface OH-groups and these groups facilitate adsorption and activation of O2 molecules, which is the key step of the oxidation reactions. The structure of the oxygen vacancies at bridging O2- sites is proposed. Also a new mechanism for the photocatalytic formaldehyde decomposition with the Au-TiO2 catalysts is proposed: The visible light absorbed by the gold nanoparticles, due to surface plasmon resonance effect, induces transition of the 6sp electrons of gold to high energy levels. These energetic electrons can migrate to the conduction band of TiO2 and are seized by oxygen molecules. Meanwhile, the gold nanoparticles capture electrons from the formaldehyde molecules adsorbed on them because of gold’s high electronegativity. O2 adsorbed on the TiO2 supports surface are the major electron acceptor. The more O2 adsorbed, the higher the oxidation activity of the photocatalyst will exhibit. The last part of this thesis demonstrates two innovative applications of the titanate nanostructures. Firstly, trititanate and metastable titanate (Na1.5H0.5Ti3O7) nanofibres are used as intelligent absorbents for removal of radioactive cations and heavy metal ions, utilizing the properties of the ion exchange ability, deformable layered structure, and fibril morphology. Environmental contamination with radioactive ions and heavy metal ions can cause a serious threat to the health of a large part of the population. Treatment of the wastes is needed to produce a waste product suitable for long-term storage and disposal. The ion-exchange ability of layered titanate structure permitted adsorption of bivalence toxic cations (Sr2+, Ra2+, Pb2+) from aqueous solution. More importantly, the adsorption is irreversible, due to the deformation of the structure induced by the strong interaction between the adsorbed bivalent cations and negatively charged TiO6 octahedra, and results in permanent entrapment of the toxic bivalent cations in the fibres so that the toxic ions can be safely deposited. Compared to conventional clay and zeolite sorbents, the fibril absorbents are of great advantage as they can be readily dispersed into and separated from a liquid. Secondly, new generation membranes were constructed by using large titanate and small ã-alumina nanofibres as intermediate and top layers, respectively, on a porous alumina substrate via a spin-coating process. Compared to conventional ceramic membranes constructed by spherical particles, the ceramic membrane constructed by the fibres permits high flux because of the large porosity of their separation layers. The voids in the separation layer determine the selectivity and flux of a separation membrane. When the sizes of the voids are similar (which means a similar selectivity of the separation layer), the flux passing through the membrane increases with the volume of the voids which are filtration passages. For the ideal and simplest texture, a mesh constructed with the nanofibres 10 nm thick and having a uniform pore size of 60 nm, the porosity is greater than 73.5 %. In contrast, the porosity of the separation layer that possesses the same pore size but is constructed with metal oxide spherical particles, as in conventional ceramic membranes, is 36% or less. The membrane constructed by titanate nanofibres and a layer of randomly oriented alumina nanofibres was able to filter out 96.8% of latex spheres of 60 nm size, while maintaining a high flux rate between 600 and 900 Lm–2 h–1, more than 15 times higher than the conventional membrane reported in the most recent study.

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Книги з теми "Mixed Oxide Catalyst"

Holden, John Graham. Chemical and structural investigations of some mixed oxide catalysts. Birmingham: University of Birmingham, 1985.

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Heterogeneous Catalysis of Mixed Oxides - Perovskite and Heteropoly Catalysts. Elsevier, 2013. http://dx.doi.org/10.1016/c2010-0-67978-8.

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Misono, M. Heterogeneous Catalysis of Mixed Oxides: Perovskite and Heteropoly Catalysts. Elsevier, 2013.

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Misono, M. Heterogeneous Catalysis of Mixed Oxides: Perovskite and Heteropoly Catalysts. Elsevier, 2013.

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Tommy K.M.* Chan. Oxidative coupling of methane over MnO r-MgO and CoO r-MgO mixed oxide catalysts. 1989.

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Частини книг з теми "Mixed Oxide Catalyst"

Chen, L., C. Bouchy, J. Tabatabatei, N. Winterton, J. C. Védrine, and E. G. Derouane. "Mixed Oxide Catalysts For Oxidation of Propane to Acrylic Acid: A Method For The Preparation of Realistic Catalyst Libraries and Their Quantitative Assessment." In Principles and Methods for Accelerated Catalyst Design and Testing, 291–97. Dordrecht: Springer Netherlands, 2002. http://dx.doi.org/10.1007/978-94-010-0554-8_15.

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Reji, Jimin, P. Anu Nair, Aravind B. Nair, S. Anas, Rahul Reji, and A. S. Akshay. "Experimental Studies on the Effect of Mixed Metal Oxide DeNox Catalyst on the Control of CI Engine Exhaust Emission." In Springer Proceedings in Materials, 271–77. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-6267-9_32.

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Yentekakis, Ioannis V., and Michalis Konsolakis. "Three-Way Catalysis." In Perovskites and Related Mixed Oxides, 559–86. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527686605.ch25.

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Roger, Anne-Cécile, and Alain Kiennemann. "Perovskites as Catalyst Precursors for Fischer-Tropsch Synthesis." In Perovskites and Related Mixed Oxides, 631–58. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527686605.ch28.

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Bueno-López, Agustín. "Progresses on Soot Combustion Perovskite Catalysts." In Perovskites and Related Mixed Oxides, 437–50. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527686605.ch19.

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Brackmann, Rodrigo, Ricardo Scheunemann, Andre Luiz Alberton, and Martin Schmal. "FexZr1−xO2and Ce1−xFexO2−δMixed Oxide Catalysts DRIFTS Analyses of Synthesis Gas and TPSR of Propane Dry Reforming." In Perovskites and Related Mixed Oxides, 659–74. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527686605.ch29.

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Huang, Xiaoming, Tamás I. Korányi, and Emiel J. M. Hensen. "Lignin Depolymerization Over Porous Copper-Based Mixed-Oxide Catalysts in Supercritical Ethanol." In Nanoporous Catalysts for Biomass Conversion, 231–51. Chichester, UK: John Wiley & Sons, Ltd, 2017. http://dx.doi.org/10.1002/9781119128113.ch10.

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Berry, Frank J. "The Application of Mössbauer Spectroscopy to Metallic, Bimetallic, and Mixed Metal Oxide Catalysts." In Industrial Applications of the Mössbauer Effect, 649–65. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4613-1827-9_36.

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Baksi, Arnab, David L. Cocke, Andrew Gomes, John Gossage, Mark Riggs, Gary Beall, and Hylton McWhinney. "Characterization of Copper-Manganese-Aluminummagnesium Mixed Oxyhydroxide and Oxide Catalysts for Redox Reactions." In Characterization of Minerals, Metals, and Materials 2016, 151–58. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119263722.ch18.

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Centi, G., S. Perathoner, and F. Vazzana. "Catalysis Using Guest Single and Mixed Oxides in Host Zeolite Matrices." In Catalysis by Unique Metal Ion Structures in Solid Matrices, 165–86. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/978-94-010-0782-5_11.

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Тези доповідей конференцій з теми "Mixed Oxide Catalyst"

Ramis, Gianguido, Guido Busca, Tania Montanari, Michele Sisani, and Umberto Costantino. "Ni-Co-Zn-Al Catalysts From Hydrotalcite-Like Precursors for Hydrogen Production by Ethanol Steam Reforming." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33034.

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A series of well crystallized Ni-Co-Zn-Al LDHs materials has been prepared by the urea hydrolysis method as precursors of mixed oxide catalysts for the Ethanol Steam Reforming (ESR) reaction. The calcination of the layered precursors gives rise to high surface area mixed oxides, mainly a mixture of rock-salt phase (NiO), wurtzite phase (ZnO) and spinel phase. Both precursors and mixed oxides have been throughtfully characterized and the steam reforming of ethanol has been investigated over the calcined catalysts in flow reactor and in-situ FT-IR experiments. The data here reported provide evidence of the good catalytic activity of Co-Zn-Al and Co-Ni-Zn-Al catalysts prepared from hydrotalcite-like LHD precursors for ethanol steam reforming. At 823 K the most active Co/Ni catalyst containains a predominant spinel phase with composition near Zn0.58Ni0.42[Al0.44Co0.56]2O4 and small amounts of NiO and ZnO. On the other side, at 873 K the selectivity to hydrogen increases with cobalt content. In particular, the presence of cobalt increases selectivity to H2 and CO2 and decreases selectivity to methane in the low temperature range 720–870 K. The most selective catalyst is the Ni-free Co-Zn-Al mixed oxide essentially constituted by a single spinel type phase Zn0.55Co0.45[Al0.45Co0.55]2O4. Cobalt catalysts appear consequently to behave better than nickel based catalysts in this temperature range. The key feature for high selectivity to hydrogen is proposed to be associated to a stability of a relatively high oxidation state at the catalyst surface, the most relevant selectivity determining step being constituted by the evolution of surface acetate species. In fact, over oxidized catalyst surface the acetate species evolve producing carbon dioxide and hydrogen while over a more reduced surface they evolve giving rise to methane and COx. Water is supposed to have the main role of allowing surface sites to stay in an unreduced state at least in the temperature range 720–870 K.

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Gohain, Minakshi, and Dhanapati Deka. "Water Hyacinth Derived Mixed-Oxide Heterogeneous Catalyst for Biodiesel Production." In 2018 2nd International Conference on Energy, Power and Environment: Towards Smart Technology (ICEPE). IEEE, 2018. http://dx.doi.org/10.1109/epetsg.2018.8658926.

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Zengjian, Zhang, Wan Hui, and Guan Guofeng. "Catalytic Combustion of Methyl Acetate over Cu-Mn Mixed Oxide Catalyst." In 2011 International Conference on Computer Distributed Control and Intelligent Environmental Monitoring (CDCIEM). IEEE, 2011. http://dx.doi.org/10.1109/cdciem.2011.107.

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Tursiloadi, S., A. Kristiani, S. N. Aisyiyah Jenie, and J. A. Laksmono. "Catalytic activity of titania zirconia mixed oxide catalyst for dimerization eugenol." In INTERNATIONAL SYMPOSIUM ON APPLIED CHEMISTRY (ISAC) 2016. Author(s), 2017. http://dx.doi.org/10.1063/1.4973181.

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Ohno, Hiroshi, Toshikatsu Takanohashi, Nobuaki Takaoka, Osamu Kuroda, and Hidehiro Iizuka. "NOx Conversion Properties of a Mixed Oxide Type Lean NOx Catalyst." In SAE 2000 World Congress. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2000. http://dx.doi.org/10.4271/2000-01-1197.

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Wilhelm, Cole, Evan Schaffer, Thomas Welles, and Jeongmin Ahn. "Experimental Investigation of the Manufacturing of Porous Solid Oxide Fuel Cells." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-69235.

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Abstract Solid oxide fuel cells (SOFCs) are typically operated in a dual-chamber setup, where the fuel and oxidant flows are separated by the fuel cell. However, dual-chamber SOFCs (DCSOFCs) require sealant to keep the flows separate, meaning that rapid heating and cooling cycling could break the seal. The initial answer to this problem was a single-chamber SOFC (SC-SOFC). The SC-SOFC is simply a planar fuel cell mounted parallel to a mixed fuel and oxidant flow. This system operates through the catalytic reactions of the anode and cathode with the fuel and oxidant, respectively. The drawback of this design comes from the requirement of fuel rich flow. A fuel lean flow leads to the oxidation of the anode and failure of the cell. On the other end, a fuel rich flow will greatly decrease system efficiency as much fuel will pass the cell and be wasted, making SC-SOFCs a difficult technology to implement. This issue led to the development of a porous SOFC (PSOFC), as a variant on the SC-SOFC. The PSOFC incorporates a similar mixed flow but is mounted perpendicular to the flow with cathode upstream of anode, and a catalyst downstream of the anode with the goal of reforming exhaust into syngas for a zero-emission fuel cell. Pores through the entire cell allow the flow to reach the anode, from the cathode side of the cell. The zero-emission condition is realized with the use of hydrocarbon fuels in the mixed flow. Reactions of fuel and air in the cell result in products of CO2 and H2O, which are then reformed by the catalyst into syngas (H2 and CO). Exhaust reformation by the catalyst is possible due to the high operating temperature of SOFCs. Syngas from the cell may be used immediately for further electricity generation or stored for later use. Manufacturing of a PSOFC is carried out with additive manufacturing (3D printing). Techniques of manufacturing PSOFCs will be discussed. The catalyst layer has been omitted from cell production until electricity generation performance of the cell improves. PSOFCs tested thus far have produced under 100 mW/cm2 with an open circuit voltage (OCV) of 0.60 V. This performance is not enough to begin implementing PSOFCs in industry. However, it does set a solid base for future PSOFCs and shows that they are a viable source of power generation. With further improvement of manufacturing methods and implementation of a catalyst, PSOFCs will become an important tool in zero-emission power production.

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Lipin, P. V., E. V. Gaifullina, O. V. Potapenko, T. P. Sorokina, and V. P. Doronin. "Simultaneous conversion of vacuum gas oil and vegetable oil on cracking catalyst containing Me, Mg-Al mixed oxide." In INTERNATIONAL CONFERENCE ON PHYSICS AND CHEMISTRY OF COMBUSTION AND PROCESSES IN EXTREME ENVIRONMENTS (COMPHYSCHEM’20-21) and VI INTERNATIONAL SUMMER SCHOOL “MODERN QUANTUM CHEMISTRY METHODS IN APPLICATIONS”. AIP Publishing, 2020. http://dx.doi.org/10.1063/5.0032873.

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Tucker, David, Ayyakkannu Manivannan, Dan Haynes, Harry Abernathy, Nick Miller, Karon Wynne, and Angine´s Matos. "Evaluating Methods for Infiltration of LSCF Cathodes With Mixed Electric/Ionic Conductors for Improved Oxygen Exchange." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33214.

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Infiltration methods for improving lanthanum strontium cobalt ferrite (LSCF) cathode performance through catalyst surface modification were evaluated at the U.S. Department of Energy, National Energy Technology Laboratory. Infiltration of mixed conductors into LSCF cathodes of solid oxide fuel cells promises a low cost method of improving oxygen exchange and performance in these materials at lower temperatures. LSCF cathodes on Nickel-Yttria Stabilized Zirconia (Ni-YSZ) anode supported cells were infiltrated with strontium-doped lanthanum zirconate (LSZ) pyrochlores using two methods. An aqueous solution of nitrate salts was vacuum infiltrated into the cathodes of anode supported button cells, and the cells were heated to form the pyrochlore phase in-situ. This was compared to the efficacy of infiltrating a suspension of pyrochlore nanoparticles. Different dispersants were used to prepare the nanoparticle suspensions at varying concentrations and pH levels, and the results are compared.

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Granovskii, Mikhail, Ibrahim Dincer, and Marc A. Rosen. "Exergetic Performance Analysis of a Gas Turbine Cycle Integrated With Solid Oxide Fuel Cells." In ASME 2007 Energy Sustainability Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/es2007-36259.

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This paper deals with an exergetic performance analysis of a gas turbine cycle integrated with SOFCs with internal reforming. As the efficiency of a gas turbine cycle is mainly defined by the maximum temperature at the turbine inlet, this temperature is fixed at 1573 K for the analysis. In the cycle considered, the high-temperature gaseous flow from the turbine heats the input flows of natural gas and air, and is used to generate pressurized steam which is mixed with natural gas at the SOFC stack inlet to facilitate its conversion. The application of SOFCs provides the opportunity to reduce the exergy losses of the most irreversible process in the system: fuel combustion. Depending on the SOFC stack efficiency, the energy efficiency of the combined cycle reaches 70–80% which compares well to the efficiencies of 54–55% typical of conventional combined power generation cycles. Parametric studies are also undertaken to investigate how energy and exergy efficiencies of the integrated system change with variations in operating conditions. An increase in the efficiency of SOFCs is attained by increasing the fuel cell active area. Achieving the highest efficiency of the SOFC stack leads to a significant and non-proportional increase in the stack size and cost, and simultaneously to a decrease in steam generation, reducing the steam/methane ratio at the anode inlet and increasing the possibility of catalyst coking. Accounting for these factors, likely operating conditions of the SOFC stack in combination with a gas turbine cycle are presented.

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Golden, Steve, Zahra Nazarpoor, and Maxime Launois. "Novel Mixed Metal Oxide Structure for Next Generation Three-Way Catalysts." In SAE 2015 World Congress & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2015. http://dx.doi.org/10.4271/2015-01-1007.

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Звіти організацій з теми "Mixed Oxide Catalyst"

Habas, Susan. Comprehensive Characterization of Mixed Metal Oxide Catalysts for Enhanced Catalyst Lifetime During Bio-Based C2-C6 Oxygenates to Olefins Processes: Cooperative Research and Development Final Report, CRADA Number CRD-18-00728. Office of Scientific and Technical Information (OSTI), January 2021. http://dx.doi.org/10.2172/1764923.

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Akyurtlu, Ates, and Jale F. Akyurtle. INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES. Office of Scientific and Technical Information (OSTI), August 2001. http://dx.doi.org/10.2172/789669.

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Akyurtlu, A., and J. F. Akyurtlu. Investigation of mixed metal sorbent/catalysts for the simultaneous removal of sulfur and nitrogen oxides. Office of Scientific and Technical Information (OSTI), March 1999. http://dx.doi.org/10.2172/8818.

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Akyurtlu, Ates, and Jale F. Akyurtlu. INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES. Office of Scientific and Technical Information (OSTI), November 1999. http://dx.doi.org/10.2172/834566.

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Ates Akyurtlu and Jale F. Akyurtlu. INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES. Office of Scientific and Technical Information (OSTI), April 2000. http://dx.doi.org/10.2172/828034.

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Dr. Ates Akyurtlu and Dr. Jale F. Akyurtlu. Investigation of mixed metal sorbent/catalysts for the simultaneous removal of sulfur and nitrogen oxides. Semiannual report, Apr 1, 1998--Oct 31, 1998. Office of Scientific and Technical Information (OSTI), October 1998. http://dx.doi.org/10.2172/754426.

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