Adsorbed hydrocarbons

Sheppard N and De La Cruz C 1996 Vibrational spectra of hydrocarbons adsorbed on metals. Part I. Introductory principles, ethylene, and higher acyclic alkenesAdv. Catal. 41 1-112... 

We postulated a reaction mechanism with participation of an aromatic radical cation which was formed by one electron transfer from an aromatic hydrocarbon to copper(II) chloride. Activated alumina has electron-acceptor properties, and formation of a radical cation of an aromatic hydrocarbon adsorbed on alumina has been observed by ESR (ref. 13). Therefore, it seemed to us that alumina as a support facilitates the generation of the radical cation of the aromatic hydrocarbon. 

The phosphorescence lifetimes for the p-aminobenzoic acid anion adsorbed on sodium acetate as a function of temperature were evaluated in a manner similar to the one discussed by Oelkrug and coworkers (,28-30) for polycyclic aromatic hydrocarbons adsorbed on y-alumina. In general, the solid-surface phosphorescence lifetime cutrves for the anion of p-aminobenzoic acid followed Equation 2. 

Behymer, T.D., Hites, R.A. (1985) Photolysis of polycyclic aromatic hydrocarbons adsorbed on simulated atmospheric particulates. 

Saturable dye absorber, 14 677 Saturated aqueous salt solution, 9 34 Saturated calomel electrode (SCE), 9 571 Saturated fatty acids, 10 829, 830 Saturated hydrocarbons adsorbent affinity, 1 674 adsorption by zeolites, 1 624 fluorine reactivity with, 11 831 isomerization of, 12 172—173 Saturated polyester resins, based on trimethylpentanediol, 12 673 Saturated polyesters, 10 7 Saturated synthetic rubber, 10 705 Saturation and coating processes, 10 12-13 Saturation bonding, 17 509-510 Saturation color, 19 262 Saturation concentration, 15 677 Saturation index... 

During a temperature scan from RT to 1100°C the effusion of C02 and H20 has been observed from an anodic oxide film, as shown in Fig. 5.8. The detected amount of C02 could be explained by a monolayer of hydrocarbons adsorbed on... 

The difficulties associated with the classical theories may be resolved if the results are interpreted in terms of a third mode of adsorption whereby unsaturated hydrocarbons adsorb on group VIII transition... 

Fig. II. (a) Schematic representation of hydrocarbons adsorbed on the [111] plane of platinum. Intersections of the lines of triangular net denote positions of the centers of platinum atoms. (1) Cyclohexane (2) all-cis conformation of cij-l,3,5-hexatriene (3) transoid conformations of cis- and trans-1,3,5-hexatriene (S4). (b) Adsorption configurations of acetylene and ethylene found most probable according to LEED studies 141).

The very rapid hydrogen isotope exchange in any hydrocarbons adsorbed over the metals in question indicates a rapid dissociation of their C—H bonds. The degree of dissociation is governed by the amount of hydrogen present. 

Photochemical transformation of benzole (e)pyrene (BeP), a polycyclic aromatic hydrocarbon, adsorbed on silica gel and alumina surfaces, is reported by Fioressi and Arce (2005). This study was designed to define the atmospheric degradation of the PAH adsorbed on particulates that originated from wind erosion of the land surface. It can be assumed that similar behavior occurs at the land surface-atmosphere interface. 

Behymer, T. D., and R. A. Hites, Photolysis of Polycyclic Aromatic Hydrocarbons Adsorbed on Simulated Atmospheric Particulates, Environ. Sci. Technol., 19, 1004-1006(1985). 

Butler, J. D., and P. Crossley, "Reactivity of Polycyclic Aromatic Hydrocarbons Adsorbed on Soot Particles, Atmos. Environ., 15, 91-94 (1981). 

Pitts, J. N., Jr., H.-R. Paur, B. Zielinska, J. Arey, A. M. Winer, T. Ramdahl, and V. Mejia, Factors Influencing the Reactivity of Polycyclic Aromatic Hydrocarbons Adsorbed on Filters and Ambient POM with Ozone, Chemosphere, 15, 675-685 (1986). 

Ramdahl, T., A. Bjprseth, D. Lokensgard, and J. N. Pitts, Jr., Nitration of Polycyclic Aromatic Hydrocarbons Adsorbed to Different Carriers in a Fluidized Bed Reactor, Chemosphere, 13, 527-534 (1984b). 

Initially, all the hydrocarbon is adsorbed on the core and none is observed at the outlet. Once the core is saturated, hydrocarbon breakthrough is observed. Example breakthrough curves for two temperatures are shown in Fig. 27. The amount of hydrocarbon adsorbed is given by the area above the breakthrough curve (after correction for the residence time of the reactor). By conducting experiments with different hydrocarbon concentrations and at different temperatures, the temperature and concentration dependency of the amount stored can be determined and hence isotherms generated. 

The form of the isotherms of the mixtures is largely independent of the cation distribution within the cage, i.e., whether the cation-poor or cation-rich model is used. This result is somewhat surprising, especially in view of the different adsorbate structures predicted by single-component isotherms (118-120). Only nonpolar adsorbates were considered in this study and the insensitivity to cation arrangement may well change if one component possesses a permanent dipole. These simulations were based on simple spherical molecules, but the competition for pore space as it depends on size, shape, and polarizability may be extended to other adsorbates. Indeed, Santilli et al. (129) observed experimentally that a branched hydrocarbon adsorbs in preference to a linear one at low loading. 

Fig. 6. SER spectra of hydrocarbons adsorbed on cold-deposited silver (A) ethyne (B) ethene (C) ethane (D) benzene. [(A) reprinted from Ref. 97, J. Electron Spectrosc. Relat. Phenom. 29, I. Pockrand, C. Pettenkofer, and A. Otto, p. 409. Copyright 1983 with kind permission of Elsevier Science-NL, Sara Burgerhartstraat 25, 1055 KV Amsterdam, The Netherlands (B) and (C) reprinted from Ref. 98, Surf. Sci. 188, C. Pettenkofer, I. Mrozek, T. Bornemann, and A. Otto, p. 519. Copyright 1987 with kind permission of Elsevier Science-NL, Sara Burgerhartstraat 25, 1055 KV Amsterdam, The Netherlands (D) reprinted from Ref. 99, J. Electron Spectrosc. Relat. Phenom. 54/55, J. Mrozek and A. Otto, p. 895. Copyright 1990 with kind permission of Elsevier Science-NL, Sara Burgerhartstraat 25,1055 KV Amsterdam, The Netherlands.]...

Sheppard and De La Cruz complete their two-part treatise on the vibrational spectra of hydrocarbons adsorbed on metals the first part of this... 

Adsorption sequence Total C4 Hydrocarbon adsorbed c Amount of C02 normally desorbed 8... 

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