Adsorption and methanation of carbon dioxide on a nickel/silica catalyst

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

DOI:https://doi.org/10.1016/0021-9517(80)90456-X· OSTI ID:7141783

Falconer, J L; Zagli, A E

The adsorption and methanation of carbon dioxide on a nickel/silica catalyst were studied using temperature-programmed desorption and temperature-programmed reaction. Carbon dioxide adsorption on nickel was found to be activated; almost no adsorption occurred at room temperature, but large coverages were obtained between 383 and 473 K. The data indicate CO/sub 2/ dissociates upon adsorption at elevated temperatures to yield carbon monoxide and oxygen atoms. These oxygen atoms react with hydrogen at room temperature, so the methane and water observed during programmed heating in flowing hydrogen are identical for adsorbed CO and adsorbed CO/sub 2/. Single CH/sub 4/ and H/sub 2/O peaks, each with a peak temperature at 473 K, were observed. This peak temperature did not change with initial coverage, indicating methanation is first order in CO surface coverage. The activated adsorption of CO/sub 2/ allowed these coverage variation experiments to be carried out. Thus, following adsorption, CO and CO/sub 2/ methanation proceed by the same mechanism. However, the activated adsorption of CO/sub 2/ may create a higher H/sub 2/:CO surface ratio during steady-state hydrogenation, causing CO/sub 2/ hydrogenation to favor methane over higher hydrocarbons. 5 figures.

• Research Organization: Univ. of Colorado, Boulder
• OSTI ID: 7141783
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 62:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ADSORPTION
ALKANES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
DISSOCIATION
ELEMENTS
HIGH TEMPERATURE
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGENATION
MEDIUM TEMPERATURE
METALS
METHANATION
METHANE
NICKEL
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
SEMIMETALS
SILICON
SORPTION
TRANSITION ELEMENTS
WATER