Propane adsorbed

In contrast, an extremely low activity was observed for the gallium-modified silicalite-1. scrambling started first at 723 K, which clearly indicates that Bronsted acid sites are necessary to activate propane adsorbed on zeolites Ga/ HZSM-5 179,181. A low activity was also observed for C-2-propane adsorbed on zeolite HZSM-5 in the absence of gallium. On this catalyst, C scrambling was observed after heating at 573 K for 20 min, and the theoretical 2 1 ratio of the signal intensities of methyl and methylene groups was reached after 80 min at 573 K. 

Kubokawa et alP also studied by i.r. spectroscopy the oxidation, by both O2 and N2O, of acrolein and propanal on ZnO. An alkoxide species, produced by scission of the O—C(2>H bond of the epoxy ring and with electron donation to the surface, was formed initially from acrolein. With time, this species dehydrogenated to an enolate complex, CH3—CH—CH—O, which was oxidized in presence of O2 at 400 K to formate and acetate species. As with propene, only propionate species were produced by oxidation with N2O. An enol-type species on ZnO has also been reported for acetone, as deduced from studies of hydrogen redistribution between [ Hq]- and [ Hel-acetone. Propanal adsorbed by co-ordination with the carbonyl group. From this species both O2 and N2O produced principally propionate species, scission of C—C bonds occurring to a much smaller extent. The above differences in ease of C—C scission were concluded to be due to the enolate species from acrolein. 

Assume we are going to place a large adsorption bed underneath our automobile to store adsorbed propane, which, we desorb while driving, to use as ia fuel replacement for liquid gasoline. Let s assume that propane adsorbs on the adsorbent material as a Langmuir isotherm,... 

We consider a system of adsorption of ethane, propane and nitrogen onto activated carbon at 303 K and a total pressure of 1 atm. At this temperature, ethane and propane adsorb onto activated carbon, and their adsorption isotherm can be adequately described by a Langmuir equation. The isotherm parameters for nitrogen, ethane and propane are ... 

FIG, 6 Plots of the amounts of methane and propane adsorbed versus the mole fraction of methane for Ajax activated carbon. Total pressure is 500 torr, and the temperature is 303 K. 

Figure 4 Distribution functions for propane adsorbed on Nuxit charcoal at temperatures of (a) 20 °C, (b) 40 °C, (c) 60 °C, and (d) 90 °C. The isotherm data were fitted to the Toth equation and analysed using the local Langmuir equation. The distributions have been recalculated using equation (89), constants given by Toth et...

Adsorption microcalorimetry of propane reveals that the surface chemistry of the carbons has no relevance in the heat of adsorption. However, the amount of propane adsorbed can vary in the oxidized carbon with the progressive removal of the oxygen groups that may block part of the microporosity. 

Stepanov A, Ernst H, Freude D (1998) In situ H MAS NMR studies of the H/D exchange of deuterated propane adsorbed on zeolite H-ZSM-5. Catal Lett 54(1) ... 

C NMR spectra of CH4 in an AIPO4-II molecular sieve have revealed exchange effects between adsorbed and nonadsorbed methane gas. The diffusion of a mixture of methane and xenon in the zeoHte siUcahte has been studied by pulsed field gradient NMR spectroscopy. In situ H MAS NMR studies of the H/D exchange of deuterated propane adsorbed on H-ZSM-5 have been reported. C MAS NMR spectroscopy has been used to study the initial stages of propane activation over H-ZSM-5, and sorption properties of hnear alkanes in ferrierite. Protonated sites on sulfate-promoted zirconium oxide catalysts have been studied using H NMR spectroscopy. NMR relaxation and self-diffusion of pentane, neopentane, dodecane, benzene, cyclohexane, and... 

Stepanov AG, Arzumanov SS, Luzgin MV, Ernst H, Freude D, Patmon VN. In situ H and C MAS NMR study of the mechanism of H/D exchange for deuterated propane adsorbed on HZSM-5. J Catal 2005 235 221-8. 

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