Catalytic anisotropy of MoO/sub 3/ in oxidation reactions in the light of bond-strength model of active sites

Journal Article · Fri Apr 01 04:00:00 EST 1983 · J. Catal.; (United States)

OSTI ID:5748610

Ziolkowski, J

Catalytic anisotropy of molybdic oxide in oxidation of propylene has been observed. High selectivity to acrolein in the indicated reaction was ascribed to the (100) plane while the (010) plane was found to yield CO/sub 2/. The critical discussion of Volta's experimental data, performed in this paper, has shown that they may be interpreted in three alternative ways, differing in the ascription of the reaction products to the crystallographic planes. Different crystallographic planes exposed by the grains of MoO/sub 3/ have been analyzed in terms of the bond-strength model of active sites developed under the following main assumptions: (i) the reaction path depends on the number and configuration of the active oxygen atoms in the vicinity of the adsorption site, and (ii) the individual catalytic activity of a given surface oxygen atom is proportional to the reciprocal sum of the strength of the bonds to it from the adjacent cations. The analysis provided the arguments to indicate the most probable reaction pattern. According to it the main products expected to be formed in oxidation of propylene on different planes of MoO/sub 3/ are (100), CO, CO/sub 2/; (001), acrolein (acrylic acid, C/sub 2/-O, CO, CO/sub 2/--mainly at longer contact time); (101) and (101), acrolein; (010), inactive (possible minor yield of hexadiene and benzene).

• Research Organization: Polish Academy of Sciences, Krakow, Poland
• OSTI ID: 5748610
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 80:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400100* -- Analytical & Separations Chemistry
ACROLEIN
ADSORPTION
ALDEHYDES
ALKENES
ANISOTROPY
AROMATICS
BENZENE
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL BONDS
CHEMICAL REACTIONS
CRYSTALLOGRAPHY
DIENES
ELEMENTS
HYDROCARBONS
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
POLYENES
PROPYLENE
SORPTION
TRANSITION ELEMENT COMPOUNDS