Theory of Adsorption of the Isotopic Hydrogen Molecules at Low Temperatures

1964 ◽  
Vol 40 (11) ◽  
pp. 3183-3194 ◽  
Author(s):  
A. Katorski ◽  
David White
Keyword(s):  
Low Temperatures ◽  
Isotopic Hydrogen ◽  
Hydrogen Molecules

scholarly journals The chemical constant of hydrogen vapour and the entropy of crystalline hydrogen

1931 ◽  
Vol 130 (813) ◽  
pp. 367-379 ◽  
Keyword(s):  
Vapour Pressure ◽  
Low Temperatures ◽  
Hydrogen Gas ◽  
Para Hydrogen ◽  
Bose Statistics ◽  
Hydrogen Molecules ◽  
Quantum Numbers ◽  
A Value ◽  
Classical Statistics ◽  
Chemical Constant

In a paper called "The Chemical constant of Hydrogen Vapour and the failure of Nernst's Heat Theorem," R. H. Fowler has investigated the vapour pressure of hydrogen crystals at low temperature; taking account of the existence of two sorts of hydrogen molecules, namely, ortho-hydrogen with even rotational quantum numbers and para-hydrogen with odd rotational quantum numbers, which retain their individuality over long periods at very low temperatures. By the use of the classical statistics, he was able to show that at very low temperatures hydrogen, as obtained by cooling hydrogen gas from ordinary temperatures, ought to have very nearly the experimentally observed chemical constant. Since the theory of the specific heat of hydrogen yielded correct values at low temperatures, it followed that at ordinary temperatures also his theory would yield a correct value for the chemical constant. Finally from the form of the partition function for hydrogen gas, Fowler attempted to obtain inferences concerning the validity of Nernst's heat theorem. By the use of the classical statistics fairly accurate results were obtained. But we shall find that when we make use of the Einstein-Bose statistics-the correct statistics for an assembly of hydrogen moleclues-a result will be obtained for the vapour pressure of hydrogen crystals at low temperatures which will furnish a value for the chemical constant of hydrogen in even closer agreement with experiment than Fowler's result.

Surface Properties and Gas Adsorption

2003 ◽  
Author(s):  
Toshiaki Enoki ◽  
Morinobu Endo ◽  
Masatsugu Suzuki
Keyword(s):  
Alkali Metal ◽  
Activated Charcoal ◽  
Low Temperatures ◽  
Gas Adsorption ◽  
Hydrogen Adsorption ◽  
Hydrogen Chemisorption ◽  
Guest Molecules ◽  
Hydrogen Molecules ◽  
General Aspects ◽  
Stage 1

It is well known that alkali metal binary GICs adsorb gaseous species (H2, N2, Ar, CH4, etc.) physisorptively at low temperatures, where physisorbed gaseous molecules are accommodated in the interstitials of the alkali metal lattice within the graphitic galleries (Lagrange and Hérold, 1975; Lagrange et al., 1972, 1976; Watanabe et al., 1971, 1972, 1973). The capacity for hydrogen adsorption, which is estimated at 144 cm3/g in KC24, for example, is large and comparable to the capacity in other adsorbers such as zeolite or activated charcoal. Interestingly, the physisorption phenomenon in alkali metal GICs has different features from that in conventional adsorbents such as zeolite or activated charcoal; that is, guest molecules in alkali metal GICs are not simply bonded to the adsorbents through weak van der Waals forces without any change in the electronic structures. Here we discuss the gas physisorption phenomenon in alkali metal GICs from general aspects, in relation to their specific features. Then in subsequent sections, we will give details of actual cases. Hydrogen is a typical gaseous molecule adsorbed in alkali metal GICs. Hydrogen physisorption takes place at low temperatures below about 200 K, where hydrogen molecules are accommodated in the graphitic galleries and are not dissociated into atomic hydrogen species. When the temperature is increased to over 200 K, the alkali metal GICs work as catalysts to hydrogen, resulting in the occurrence of hydrogen chemisorption. Hydrogen physisorption will be discussed in Section 8.1.2, hydrogen chemisorption and related issues have been discussed partly in Sections 2.2.1 and 5.4.1 from the viewpoints of structure and electronic properties, and will be discussed again in Section 8.1.2. Figure 8.1 represents the composition dependence of the amount of physisorption of hydrogen molecules in KCm at 77 K (Lagrange and Hérold, 1975). The composition of 1/m = 1/8 corresponds to the stage-1 compound and the composition 1/m = 1/24 to the stage-2 compound; intermediate compositions between 1/8 and 1/24 are considered to have a mixed structure of stage-1 and stage-2 compounds. The stage-1 compound does not adsorb hydrogen at all.

scholarly journals THE PHYSICS OF LIQUID PARA-HYDROGEN

2006 ◽  
Vol 20 (30n31) ◽  
pp. 5035-5046 ◽  
Author(s):  
THOMAS LINDENAU ◽  
MANFRED L. RISTIG ◽  
KLAUS A. GERNOTH ◽  
JAVIER DAWIDOWSKI ◽  
FRANCISCO J. BERMEJO
Keyword(s):  
Experimental Data ◽  
Low Temperatures ◽  
Normal Phase ◽  
Para Hydrogen ◽  
Boson Systems ◽  
Path Integral Monte Carlo ◽  
Fundamental Interest ◽  
Hydrogen Molecules ◽  
Thermodynamic Phase ◽  
Theoretical Results

Macroscopic systems of hydrogen molecules exhibit a rich thermodynamic phase behavior. Due to the simplicity of the molecular constituents a detailed exploration of the thermal properties of these boson systems at low temperatures is of fundamental interest. Here, we report theoretical and experimental results on various spatial correlation functions and corresponding distributions in momentum space of liquid para-hydrogen close to the triple point. They characterize the structure of the correlated liquid and provide information on quantum effects present in this Bose fluid. Numerical calculations employ Correlated Density-Matrix (CDM) theory and Path-Integral Monte-Carlo(PIMC)simulations. A comparison of these theoretical results demonstrates the accuracy of CDM theory. This algorithm therefore permits a fast and efficient quantitative analysis of the normal phase of liquid para-hydrogen. We compare and discuss the theoretical results with available experimental data.

scholarly journals The isotopic Exchange between Hydrogen and Water on Platinum. Relative Rates of Exchange of Isotopic Hydrogen Molecules.

1956 ◽  
Vol 10 ◽  
pp. 655-666 ◽  
Author(s):  
Kåre Hannerz ◽  
Lars Gunnar Sillén ◽  
Ulf Ulfvarson ◽  
Einar Stenhagen ◽  
B. Thorell
Keyword(s):  
Isotopic Exchange ◽  
Isotopic Hydrogen ◽  
Hydrogen Molecules

Calculated fusion rates in isotopic hydrogen molecules

Nature ◽  
1989 ◽  
Vol 339 (6227) ◽  
pp. 690-691 ◽  
Author(s):  
S. E. Koonin ◽  
M. Nauenberg
Keyword(s):  
Isotopic Hydrogen ◽  
Hydrogen Molecules

Diffusion of isotopic hydrogen molecules in Ar and Kr

Physica ◽  
1974 ◽  
Vol 75 (3) ◽  
pp. 560-572 ◽  
Author(s):  
A.S.M. Wahby ◽  
A.J.H. Boerboom ◽  
J. Los
Keyword(s):  
Isotopic Hydrogen ◽  
Hydrogen Molecules

scholarly journals The chemical constant of chlorine vapour and the entropy of crystalline chlorine

1931 ◽  
Vol 131 (817) ◽  
pp. 339-354 ◽  
Keyword(s):  
Gaseous Phase ◽  
Vapour Pressure ◽  
Low Temperatures ◽  
Hydrogen Gas ◽  
The Other ◽  
Ortho Hydrogen ◽  
Bose Statistics ◽  
Hydrogen Molecules ◽  
Classical Statistics ◽  
Chemical Constant

In a recent paper the writer calculated the vapour pressure of hydrogen crystals, using the Einstein-Bose statistics for the gaseous phase. The work was an extension of that of R. H. Fowler, who had used the slightly less accurate classical statistics for the hydrogen gas. In this paper we propose to apply similar methods of investigation to chlorine. The investigation will have to be different in some respects, however. Hydrogen was considered to consist of a mixture of two gases, para- and ortho-hydrogen, which retained their individuality over long periods of time at low temperatures. Due to the existence of two isotopes of chlorine, we shall here have five gases to consider instead of two. Further, hydrogen molecules almost certainly can rotate quite freely in the crystals of hydrogen; on the other hand, molecules of chlorine almost certainly can not rotate at all in crystals of chlorine.

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