Kinetics and selectivity of 2-propanol conversion on oxidized anatase TiO{sub 2}

Journal Article · Wed Jan 01 04:00:00 EST 1997 · Journal of Catalysis

DOI:https://doi.org/10.1006/jcat.1997.1467· OSTI ID:476838

Rekoske, J E; Barteau, M A ^[1]

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1. Univ. of Delaware, Newark, DE (United States)

The steady-state kinetics of 2-propanol decomposition on oxidized anatase TiO{sub 2} have been determined at temperatures ranging from 448 to 598 K and 2-propanol partial pressures from 8.9 to 102.7 Torr. The effects of the addition of O{sub 2} and water to the carrier gas were also investigated. The steady-state reaction results primarily in the formation of a dehydration product, propylene, and a dehydrogenation product, acetone, with small amounts of carbon oxides also being observed. Depending on the reaction conditions, the selectivity to either propylene or acetone can range between 5 and 95%. The rate of dehydrogenation increases dramatically with the addition of both O{sub 2} and water, while the dehydration rate is unaffected by their presence. Accordingly, the kinetics of 2-propanol decomposition were investigated using both air and an inert carrier. Using air as the carrier gas, the dehydration and dehydrogenation reactions were determined to be approximately one-half order with respect to 2-propanol partial pressure. The activation energies determined for the two processes are substantially different, 68 kJ mol{sup -1} for dehydrogenation and 130 kJ mol{sup -1} for dehydration, as evidenced by the strong temperature dependence of the decomposition selectivity. Using an inert carrier, the reaction kinetics depend in a complex fashion on the conversion of 2-propanol. The dependence on conversion was found to arise from the influence of water on the dehydrogenation kinetics. The presence of water, whether produced by 2-propanol dehydration or added independently, was found to increase the rate of 2-propanol dehydrogenation. 48 refs., 9 figs., 6 tabs.

• OSTI ID: 476838
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 1 Vol. 165; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
DEHYDRATION
DEHYDROGENATION
HETEROGENEOUS CATALYSIS
PROPANOLS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K
TITANIUM OXIDES