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Zhang, Xunli; Hayward, D.; Mingos, D. Michael P.

doi:10.1023/a:1022672219909

Cited by 81 publications

(61 citation statements)

References 21 publications

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“…Based on the observation that microwave dielectric heating can accelerate the reaction rate in general and even result in ''apparent'' shifts in the equilibrium constant of reactions, this advanced heating method has been employed for the catalytic reforming of methane with carbon dioxide over Pt catalysts [54]. This reaction can be represented as:…”

Section: Reforming Of Methane With Carbon Dioxidementioning

confidence: 99%

“…The research has been focused on the application of microwave dielectric heating in a range of chemical processes including the synthesis of superconducting ceramics [31] and other inorganic materials [33][34][35][36][37][38][39][40][41], the synthesis of organometallic compounds [42,43], solid-state reactions involving metal powders [44][45][46][47][48], and more recently heterogeneous catalytic reactions [49][50][51][52][53][54][55]. Advances have also been made in understanding dielectric heating behaviour [24,29,50,52,56].…”

Section: Introductionmentioning

confidence: 99%

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Applications of microwave dielectric heating in environment-related heterogeneous gas-phase catalytic systems

Zhang

Hayward

2006

Inorganica Chimica Acta

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167

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The application of microwave dielectric heating in a range of environment-related heterogeneous catalytic reaction systems has been reviewed. The reactions investigated include the decomposition of hydrogen sulfide, the reduction of sulfur dioxide with methane, the reformation of methane by carbon dioxide, the hydrodesulfurization of thiophene, and the oxidative coupling of methane. The interaction of microwave irradiation with heterogeneous catalytic systems and its consequence for the microwave heating behaviour of catalysts have been examined. The effect/mechanism of microwave dielectric heating on heterogeneous catalytic reaction systems has also been discussed.

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Section: Reforming Of Methane With Carbon Dioxidementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Applications of microwave dielectric heating in environment-related heterogeneous gas-phase catalytic systems

Zhang

Hayward

2006

Inorganica Chimica Acta

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167

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“…A wide class of these reactions is the oxidation of hydrocarbons over transition metals. For instance, self-sustained rate oscillations have been noted in the oxidation of methane, ethane, propane, and butane over supported and unsupported catalysts based on Ni, Co, Pd, Pt, Rh, and Ru [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The distinctive features of these oscillations are their long periods, ranging from several seconds to tens of minutes, and an induction period before the appearance of the regular oscillations.…”

Section: Introductionmentioning

confidence: 99%

Evolution of self-sustained kinetic oscillations in the catalytic oxidation of propane over a nickel foil

Каичев

Teschner

Saraev

et al. 2016

Journal of Catalysis

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The evolution of self-sustained reaction-rate oscillations in the catalytic oxidation of propane over a nickel foil has been studied in situ using X-ray photoelectron spectroscopy coupled with on line mass spectrometry and gas chromatography. Changes in the effective surface area and in the catalyst morphology under reaction conditions have been examined by scanning electron microscopy and a krypton adsorption technique. It is shown that the regular kinetic oscillations arise under oxygen-lean conditions. CO, CO 2 , H 2 , H 2 O, and propylene are detected as products.The conversion of propane oscillates in a range from 1% to 23%. During the half-periods with high activity, the main reaction pathway is the partial oxidation of propane: selectivity toward CO achieves 98%. In contrast, during the half-periods with low activity, the reaction proceeds through three competitive pathways: the partial oxidation of propane, the total oxidation of propane, and the dehydrogenation of propane to propylene. The driving force for the selfsustained kinetic oscillations is the periodic reoxidation of nickel. According to the Ni2p and O1s core-level spectra measured in situ, the high-active catalyst surface is represented by metallic nickel, whereas during the inactive half-periods the catalyst surface is covered with a thick layer of NiO. The intensity of O1s spectra follows the oscillations of O 2 in the gas phase during the oxidation of propane. It is found that during the induction period before the regular oscillations appear, a rough and porous structure develops because of strong reconstruction of the catalyst surface. The thickness of the reconstructed layer is approximately 10-20 µm. This process is accompanied with at least an 80-fold increase in the effective surface area compared with a clean, non-treated nickel foil, which undoubtedly leads to a drastic increase in the number of active sites. We believe that it is the main reason for the induction period always being  Corresponding author.E-mail address: vvk@catalysis.ru (V.V. Kaichev) 2 observed before the appearance of self-sustained oscillations in the catalytic oxidation of light hydrocarbons over catalysts with a low specific surface area (single crystals, foils, or wires).Moreover, without such reconstruction, the oscillations cannot arise due to low activity of such catalysts.

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“…However, Matsubara et al [25], studying surface temperature distribution based on the thermal radiation spectrum due to the microwave heating of iron oxides (magnetite and hematite), observed the creation of local hot domains in the order of tens lm which generated huge temperature gradient of *200-400°C. Zhang et al [26] studying the catalytic decomposition of hydrogen sulfide under microwave heating postulated that observed catalyst structure reorganization, phase change from c-alumina to a-alumina at unusually low measured temperature, could be the evidence for the formation of ''hot spots'', although their exact location in the catalyst bed was difficult to determine. Generally, in every literature report, when enhancement of the catalyst oxidation behavior under microwave radiation conditions is observed, it is assigned to the ''hot spot'' formation, regardless of the physicochemical properties of the used catalyst.…”

Section: Catalytic Propertiesmentioning

confidence: 99%

Total oxidation of lean propane over α-Fe2O3 using microwaves as an energy source

Dobosz

Zawadzki

2014

Reac Kinet Mech Cat

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A combined process of catalytic oxidation and microwave heating for the treatment of lean propane-air mixture, and ''green'' hematite synthesis were described in this work. The study demonstrated that removal and oxidation efficiencies of propane over a-Fe 2 O 3 were above 99.9 % after a short microwave radiation time (from 9 min) and they were strongly dependent on the applied microwave power. Comparing to conventional heating, the catalytic performance of hematite was enhanced by lowering the operation temperature under microwave conditions. Nanocrystalline a-Fe 2 O 3 catalyst with mesoporous structure was successfully prepared by a microwave-assisted hydrothermal treatment of iron hydroxide in an aqueous solution without any alkali additive, and characterized by XRD, TEM, TPR-H 2 , FTIR and N 2 adsorption-desorption. The microwave-induced heating over hematite catalyst appears to be a very effective alternative method for air treatment to the destruction and removal of short chain hydrocarbons.

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Untitled

Cited by 81 publications

References 21 publications

Applications of microwave dielectric heating in environment-related heterogeneous gas-phase catalytic systems

Applications of microwave dielectric heating in environment-related heterogeneous gas-phase catalytic systems

Evolution of self-sustained kinetic oscillations in the catalytic oxidation of propane over a nickel foil

Total oxidation of lean propane over α-Fe2O3 using microwaves as an energy source

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