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Showing 1 to 20 of 70 for “"temperature programmed desorption"”.
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Temperature -Programmed Desorption Studies on Methanol, Benzene, and Hexafluoroacetylacetone on (2X1)pt(110)
TPD was used to study the chemistry of hexafluoroacetylacetone (Hhfac) on oxygen-precovered (2x1)Pt(110). It begins to decompose at 350 K and no platinum is chelated away. Water, carbon monoxide, carbon dioxide, a carbonaceous deposit, and fluorocarbons are the decomposition products. Hhfac is thus …
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Design of a Temperature Programmed Desorption System for the Measurement of the Desorption Kinetics of Molecules from Surfaces
Temperature programmed desorption (TPD) is an experimental technique used to measure the desorption kinetics of molecules from surfaces. This technique is performed by linearly increasing the temperature of a sample while measuring the partial pressures of the desorbing gas species. It is used to …
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Temperature Programmed Desorption and Infrared Spectroscopic Studies of Interfacial Hydrogen Bonds for Small Molecules Adsorbed on Silica and Within Metal Organic Frameworks
… study specific surface-molecule interactions and temperature-programmed desorption to measure activation energies of desorption. 2-CEES has two polar functional groups, the chloro and thioether moieties, available to accept hydrogen bonds from free surface silanol groups. Diethyl sulfide and …
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Structure Sensitivity of Ethylene Adsorption on Platinum (Dehydrogenation)
… of ethylene adsorption on platinum surfaces. Temperature Programmed Desorption (TPD), Electron Energy Loss Spectroscopy (EELS), Low-Energy Electron Diffraction (LEED) and Auger spectroscopy are applied to study the adsorption of ethylene on the square (1 x 1)Pt(100) and on the pseudo-hexagonal …
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Challenging Theories in Surface Science: Models of Active Sites and Carbon Monoxide Surface Binding
… on O/Pt(110) have been studied with temperature-programmed desorption. Unlike hexafluoropentanedione on oxygen-precovered nickel and copper, hexafluoropentanedione does not etch oxygen-precovered platinum. Hexafluoropentanedione decomposes below 350 K, yielding acetaldehyde, …
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Activity and selectivity of transition metal (Fe, Mo and W) carbides in the Fischer-Tropsch synthesis
… The carbide catalysts were prepared by a temperature programmed method. The properties of the materials were characterised by X-ray diffraction (XRD), transmission electron microscopy (TEM), BET measurements and temperature programmed desorption of carbon monoxide (CO-TPD). The performance …
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Boundary Layer Dynamics in Mixed Hydrocarbon Thin Films on Metal Surfaces
… the mobility of the molecules as a function of temperature. Temperature programmed desorption spectroscopy provides quantitation of the exchange process and isotope effects observed in these systems. For equal chain length, preferential segregation of the protio species to the surface is …
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Chemical vapor deposition of copper, copper(I) oxide, and silver from metal-organic precursors
… electron energy loss spectroscopy, and temperature programmed desorption experiments indicate that copper(I) oxide is formed by an elimination mechanism and copper metal is formed by deoxygenation of an initially deposited copper(I) oxide phase.
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Structural Characterization and Phase Behavior in Supported Metallic Nanoparticles
… X-ray absorption fine structure spectroscopy, temperature programmed desorption, and scanning-transmission electron microscopy. The data reveal that during activation in hydrogen the stabilizing CO shell is lost, and the metal centers assume an increasingly metallic electronic character. The …
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Ether Chemistry On Si(100) And Desorption Kinetics Of Corresponding Alkyls And Alkoxides
The desorption kinetics of a series of alkyls and alkoxides from the Si(100) surface weremeasured to investigate the details of the hydride elimination desorption mechanism.Following the analysis of temperature programmed desorption experiments inconjunction with electronic structure calculations, …
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Preparation and Characterization of Palladium Catalysts
… or incipient wetness, drying by room temperature or air-oven, and support choice between silica and alumina. These catalysts were prepared to meet the demand for low temperature oxidation. Results indicated a 5% increase in percent dispersion of metal across the support due to room …
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Hydrogen storage in pt/carbon nanotube sheets
… treated samples was evaluated using temperature-programmed desorption (TPD) measurement.
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The Interaction of Carbon Monoxide With Nitric Oxide and Hydrogen on Platinum
… H(,2) on Pt(410) have been investigated using Temperature Programmed Desorption. Pt(410) is found to be unusually reactive in decomposition of NO even at 120 K, as evidenced by desorption of N(,2)O below 150 K. At low exposures of NO, only the formation of N(,2) is observed. The formation of …
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The Effect of Surface Structure on the Decomposition of Nitric-Oxide and Ammonia on Platinum
Temperature programmed desorption (TPD) was used to compare nitric oxide (NO) decomposition on Pt(100), Pt(411), and Pt(211). The three surfaces were predicted to have similar orbital availabilities but different site densities. The measured dissociation fractions were 66, 70, and 66% on Pt(100), …
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The catalytic activity of anodic oxides on aluminum
… and pyridine, was studied by IR spectroscopy and temperature programmed desorption mass spectrometry. It was thus possible to differentiate between Lewis and Brønsted acid sites and to determine the quantity of the acid sites on the various oxides.
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Nanopartículas de ouro suportadas em óxidos mistos de cério e ferro para a redução de NO por CO
… conversions. NO and CO adsorption tests at room temperature, infrared spectroscopy measurements and temperature programmed desorption analyzes were carried out and allowed the proposition of reaction routes between NO and CO at different temperatures for the synthesized catalysts. It was found …
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Solid particle erosion of ceramics
… modifications were investigated primarily using temperature programmed desorption techniques. The internal surface of ZSM-5, a medium pore zeolite, plays a major role in the shape selective properties of this catalyst, due to the diffusional restrictions imposed by the channel system on bulky …
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The characterization and elimination of the external acidity of ZSM-5
… modifications were investigated primarily using temperature programmed desorption techniques. The internal surface of ZSM-5, a medium pore zeolite, plays a major role in the shape selective properties of this catalyst, due to the diffusional restrictions imposed by the channel system on bulky …
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A comparison of conventional heating techniques and microwave irradiation for the desorption of lithium borohydride and lithium borohydride composites
The desorption of lithium borohydride and lithium borohyride composites was examined using both conventional heating techniques and microwave irradiation. LiBH4 was milled with TiH2 in various molar ratios in an argon atmosphere using both roller and planetary mill techniques. Thermo-gravimetric …
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Hydrogen sorption in palladium doped microporous materials
… and chemically doped porous materials at room temperatures. XRD, Temperature Programmed Desorption and hydrogen sorption measurements were used to characterise the as-received and palladium doped porous materials. The hydrogen uptakes of as-received Maxsorb (activated carbon), Black Pearls …
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