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Showing 1 to 20 of 30 for “"Platinum catalysts."”.
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NMR studies of acetylene adsorbed on supported platinum catalysts
… adsorbed at room temperature on supported platinum catalysts.
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NMR studies of acetylene absorbed on supported platinum catalysts
… (C2H2) adsorbed at room temperature on supported platinum catalysts. Measurements from 77""K to 158°K of the spin-lattice relaxation behavior of carbon-13 reveal multiple-exponential behavior. Calculations rule out an anisotropic T 1 as an explanation for the multiple-exponential behavior. …
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Nuclear Magnetic Resonance of Platinum Catalysts: The Discovery of The Surface Resonance
… ('195)Pt NMR at 74 MHz in three samples of 10% platinum-on-alumina catalysts at 77 and 4.2(DEGREES)K. The NMR absorption lines for each sample extend from the resonance position of ('195)Pt in bulk Pt metal past the resonance position in diamagnetic Pt compounds to positive Knight shifts. The …
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Nuclear magnetic resonance of platinum catalysts: The discovery of the surface resonance
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-17T15:39:37Z No. of bitstreams: 1 1981_rhodes.pdf: 7826483 bytes, checksum: 859de26e46b8a821a733687c4b00d220 (MD5)
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Oxidation of butene over platinum catalysts in a zirconia-yttria electrochemical reactor
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1986.
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Nuclear magnetic resonance study of carbon monoxide bonded to platinum catalysts via the study of1̳3̳C T1̳'s
Submitted by William Weathers (weathrs2@illinois.edu) on 2012-04-26T22:56:48Z No. of bitstreams: 1 1997_dean.pdf: 4717677 bytes, checksum: 4bb1dc4e799efd8dac544691ceaedd07 (MD5)
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Nuclear Magnetic Resonance Study of Carbon Monoxide Bonded to Platinum Catalysts via the Study of (13)C T-1's
The reason that a $\sp{13}$C T$\sb1$ curve may fall into one class or another (wide or narrow) is not well understood, although a possible cause is the presence of varying degrees of heterogeneity at the cluster surface for different samples.
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A new approach to the study of surface phenomena, measurements of diffusion rates, intermolecular distances and electronic properties of CO chemisorbed on supported platinum catalysts by nuclear magnetic resonance
… to study the chemisorption of CO on supported platinum particles. The particles are 10 to 50 Ansgtrom in diameter, supported on alumina. CO is 90% enriched with 13CO. NMR data were taken from 4 K to 600 K. He shows that a measurement of transverse relaxation at 77 K can be used to measure …
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A New Approach to the Study of Surface Phenomena: Measurements of Diffusion Rates, Intermolecular Distances and Electronic Properties of Carbon Monoxide Chemisorbed on Supported Platinum Catalysts by Nuclear Magnetic Resonance
… to study the chemisorption of CO on supported platinum particles. The particles are 10 to 50 (ANGSTROM) in diameter, supported on alumina. CO is 90% enriched with ('13)CO. NMR data were taken from 4 K to 600 K.
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An investigation into the alkene hydroformylation reaction using platinum complexes
… both the bulk and specialty chemical industry. Platinum catalysts have shown significant chemo- and regioselectivities in alkene hydroformylation. This thesis investigates the activity as well as selectivity of platinum complexes containing bidentate ligands in the hydroformylation reaction.
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Synthesis and Biological Evaluation of Rigid Analogues of Methamphetamines
… via hydrogention over palladium and platinum catalysts. The benzylideneazetidine and benzyliazetidine analogs were evaluated at monoamine transporters as a part of preliminary structure-activity study for the development of novel monoamine transporter ligands. The binding affinities …
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Catalisadores de platina suportada em nióbia para oxidação seletiva de CO - SELOX
… for the presence of different sites in the platinum catalysts. For Pt/Nb2O5, it was seen that there is competition between the CO and O2 Pt0 sites. The low catalytic activity of Pt/Nb2O5 and Pt/Nb2O5-nano were related to the difficulty of removing the CO molecules linearly adsorbed on Pt and …
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EXPLORATION OF TM-NX ORR ELECTROCATALYSTS FROM FIRST PRINCIPLE CALCULATIONS
… current fuel cells rely on rare and expensive Platinum catalysts and the power generation is limited by the sluggish oxygen reduction reaction (ORR) at the cathode. An interesting alternative material set which continues to attract significant attention are TM-Nx (TM = Fe, Co, x = 2 - 4) based …
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The development of novel hetrogeneous catalysts for the hydrogenation of prochiral imines
Catalysts have been studied for the enantioselective hydrogenation of prochiral imines. Work has centred on the support of homogeneous catalysts, with the intention of establishing a heterogeneous catalyst without loss of activity. Initially, established heterogeneous systems were investigated. As …
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A microreactor system for high-pressure, multiphase homogeneous and heterogeneous catalyst measurements under continuous flow
… model. The hydrogenation of cyclohexene over platinum catalysts was chosen to demonstrate the performance of the heterogeneous reactor. This reaction proceeded rapidly allowing mass transfer to be characterized in the microreactor. Observed mass transfer rates were two orders of magnitude …
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Functionalized carbon surfaces for clean electrochemical energy systems
… are based on expensive materials that implement platinum catalysts on a carbon support (Pt/C). The high cost and limited availability of platinum hinders the applicability of FCs. Nitrogen and metal-doped carbon supports have been investigated as a non-precious metal replacement for costly …
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Adatom Emission From Nanoparticles: Implications for Ostwald Ripening
… of catalytic converters. Precious metal-based catalysts such as Pt and Pd are currently used in catalytic converters. To achieve higher fuel efficiency, combustion can be carried out in excess air resulting in a reduction of greenhouse gas (GHG) emissions. Reduction of these emissions has …
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The photo-oxidation of benzyl alcohol over TiO2 and Pt TiO2 and the effect of reaction conditions
… benzaldehyde. In this work, the hypothesis that platinum enhances the photocatalytic activity of titania in the photocatalytic oxidation of benzyl alcohol was tested. The titania tested was commercially sourced and the platinum was anchored on titania using a wet impregnation method, with …
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NON-PLATINUM GROUP METAL OXGYEN REDUCTION CATALYSTS AND THEIR MECHANISM IN BOTH ACID AND ALKALINE MEDIA: THE EFFECT OF THE CATALYST PRECURSOR AND THE IONOMER ON OXYGEN REDUCTION
Non-platinum catalysts are an attractive strategy for lowering the cost of fuel cells, but much more development is needed in order to replace platinum, especially at the cathode where oxygen is reduced. Research groups worldwide have donated material for a study in which precursor structure to …
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Hydrothermal and ionothermal carbon structures
… electrolyte fuel cells), compared to commercial platinum catalysts, astonishing activities are observed. In another example the selective and very cost efficient electrochemical synthesis of hydrogen peroxide is presented. In a last example the synthesis of graphitic boron carbon nitrides from …
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