Studies of ethylene hydrogenation and of adsorbed C/sub 2/H/sub 4/ and H/sub 2/ on chromia and lanthana catalysts

Journal Article · Tue Jan 01 04:00:00 EST 1980 · J. Catal.; (United States)

OSTI ID:5379477

Khodakov, Y S; Makarov, P A; Delzer, G; Minachev, K M

Adsorbed forms of C/sub 2/H/sub 4/ and H/sub 2/ (and hydrogenation of adsorbed C/sub 2/H/sub 4/ at - 78/sup 0/C) on Cr/sub 2/O/sub 3/, Cr/sub 2/O/sub 3/ . 7Al/sub 2/0/sub 3/, La/sub 2/O/sub 3/, and Al/sub 2/O/sub 3/ pretreated at 400 to 900/sup 0/C, with increments of 100/sup 0/C, have been investigated by temperature-programmed desorption. Chemical desorption of the reactants by the catalytic poisons CO, CO/sub 2/, and H/sub 2/O at - 78, -68, and 20/sup 0/C has been studied on La/sub 2/O/sub 3/. The hydrogenation activity of these oxides and the control of the poisoning of La/sub 2/O/sub 3/ in C/sub 2/H/sub 4/ hydrogenation have been researched by a circulation method at temperatures of -78, -68, and 20/sup 0/C with an equimolar mixture of C/sub 2/H/sub 4/ and H/sub 2/ at an initial pressure of 10 Torr. The results show that the catayltic activity, the number of adsorbed forms, and the adsorbed amounts of the reactants in the different forms depend on the pretreatment temperature. The distinctiveness of the adsorbed forms of the reactants originates from distinctions in the properties of adsorbed centers. The activity of the catalyst is due to the presence of at least two types of centers on the surface. Different reactivities have been found for different adsorbed C/sub 2/H/sub 4/ forms in their interaction with H/sub 2/O at -78/sup 0/C. It has been demonstrated that the poisoning effect of CO, CO/sub 2/, and H/sub 2/0 is due to adsorption displacement of the adsorbed hydrogen and ethylene. The ratio between the amount of adsorbed poison and desorbed C/sub 2/H/sub 4/ and H/sub 2/ depends on the chemical nature of the poison. 4 figures, 2 tables.

• Research Organization: Zelinskii Inst. of Organic Chemistry, Moscow, USSR
• OSTI ID: 5379477
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 61:1; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKENES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
CRYOGENIC FLUIDS
DATA
DATA FORMS
DEACTIVATION
DESORPTION
ELEMENTS
ETHYLENE
EXPERIMENTAL DATA
FLUIDS
HIGH TEMPERATURE
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGENATION
INFORMATION
ISOLATED VALUES
KINETICS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LOW PRESSURE
LOW TEMPERATURE
MEDIUM TEMPERATURE
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PRESSURE DEPENDENCE
RARE EARTH COMPOUNDS
REACTION KINETICS
SPECTROSCOPY
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
VERY HIGH TEMPERATURE
WATER