Homomolecular isotope exchange of hydrogen on nickel - chromia catalystand on nickel films

Journal Article · Sun May 01 04:00:00 EDT 1983 · Kinet. Catal. (Engl. Transl.); (United States)

OSTI ID:5135877

Zhavoronkova, K N; Perevezentseva, N N

The specific catalytic activity (K/sub sp/) of commercial Ni/Cr/sub 2/O/sub 3/ catalyst and of nickel films has been investigated in the reaction of isotope exchange in molecular hydrogen at temperatures of 77-293/sup 0/K and a pressure of 0.5mm Hg. For the nickel films, a break was observed in the Arrhenius plot at 130/sup 0/K; the values of the activation energy E for the low-temperature and high-temperature regions were 0 and 6 kJ/mole, respectively. For the Ni/Cr/sub 2/O/sub 3/ catalyst, over the entire interval of temperatures investigated, E = 10.6 kJ/mole. Warming of this catalyst over an extended period in hydrogen led to the appearance of a break on the Arrhenius line at 120/sup 0/K, below which E = 0. In the case of the nickel films, warming in hydrogen, as well as adsorption of preatomized hydrogen led to changes in the course of the temperature dependence of K/sub sp/: The break on the Arrhenius line was observed at 190/sup 0/K, with a zero activation energy below this temperature, and an activation energy above this temperature that had been increased to 30 kJ/mole. The reasons for these changes are discussed on the basis of assumptions of a difference in forms of adsorbed hydrogen. 3 figures, 1 table.

• Research Organization: D.I. Mendeleev Moscow Chemical Tech. Inst., USSR
• OSTI ID: 5135877
• Journal Information: Kinet. Catal. (Engl. Transl.); (United States), Journal Name: Kinet. Catal. (Engl. Transl.); (United States) Vol. 24:3; ISSN KICAA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400203* -- Isotope Exchange & Isotope Separation-- (-1987)
ACTIVATION ENERGY
ADSORPTION
ARRHENIUS EQUATION
CATALYSIS
CATALYSTS
CHALCOGENIDES
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
ELEMENTS
ENERGY
EQUATIONS
FILMS
HYDROGEN
ISOTOPIC EXCHANGE
LOW TEMPERATURE
MEDIUM TEMPERATURE
MEDIUM VACUUM
METALS
NICKEL
NICKEL COMPOUNDS
NICKEL OXIDES
NONMETALS
OXIDES
OXYGEN COMPOUNDS
SORPTION
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS