Ortho-para conversion of hydrogen on films of rare-earth metals

Journal Article · Sat Dec 01 00:00:00 EST 1979 · Dokl. Phys. Chem. (Engl. Transl.); (United States)

OSTI ID:5689881

Zhavoronkova, K N; Peshkov, A V

This study concerns the comparative study of the specific catalytic activity of rare-earth metals and shows how far a change in the electron structure of the metals can affect their catalytic properties. The ortho-para conversion at 77/sup 0/K has been used as the model reaction. Scandium and all the lanthanoids except europium and promethium were prepared in the form of vacuum-evaporated films. Other conditions were 0.5 torr; n/sub 0/ = 10/sup 15/ is the number of metal atoms on the surface; F/sub a/ = 1 is the proportion of paramagnetic metal atoms; and O = the degree of filling of the surface by the physically adsorbed hydrogen molecules. The results established that the rare earth metals as catalysts of a low temperature ortho-hydrogen conversion are divided into two groups which differ in the mechanism by which the reaction occurs. A comparison between the experimental results and the calculated results of the absolute rates of the paramagnetic conversion and also with the results of a study of isotopic exchange for these metals leads to the conclusion that for metals of the first group the conversion occurs by a chemical mechanism and for metals of the second group, by a vibrational magnetic mechanism. 3 figures, 1 table.

• Research Organization: Moscow Chemical-Engineering Inst., USSR
• OSTI ID: 5689881
• Journal Information: Dokl. Phys. Chem. (Engl. Transl.); (United States), Vol. 246:4-6; Other Information: Translated from Dokl. Akad. Nauk SSSR; 246: No. 6, 1395-1399(Jun 1979)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
08 HYDROGEN
HYDROGEN
SPIN ORIENTATION
RARE EARTHS
CATALYTIC EFFECTS
SCANDIUM
CATALYSTS
CHEMICAL REACTION KINETICS
EXPERIMENTAL DATA
FILMS
ISOLATED VALUES
LOW TEMPERATURE
MEDIUM VACUUM
PRESSURE DEPENDENCE
TEMPERATURE DEPENDENCE
CRYOGENIC FLUIDS
DATA
DATA FORMS
ELEMENTS
FLUIDS
INFORMATION
KINETICS
METALS
NONMETALS
NUMERICAL DATA
ORIENTATION
REACTION KINETICS
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties
080800 - Hydrogen- Properties & Composition