Combustion Kinetics of Metal Oxide and Halide Radicals and Metal Atoms.
Abstract
To help provide a better understanding of the temperature dependence of the kinetics of diatomic metal radical oxidation reactions, experimental measurements were made in the 450 to 1750 K temperature regime. An HTFFR (high-temperature fast-flow reactor) was used. The metal radical concentrations were measured by laser-induced fluorescence. The general uses of this spectrometric technique for rate measurements on reactants and products, as well as for product species identification and product state determination, are reviewed. The radicals studied in the HTFFR on this grant are ALo, AlCl and BCl. Production methods for these are discussed. For the reaction AlO + CO yields AlO2 AlO + AlO2 + CO we obtain k(T) = 2.5 X 10 to the minus 14th power exp (400/T) cc/molecules/s. This negative activation energy implies D(O-AlO) > D(O-CO) = 530 kj/mol, which is in apparent disagreement with the OAlO dissociation energy obtained for AlO2 from Al2O3 evaporation-mass spectrometry studies. It is argued that the latter AlO2 may have a different structure from that of the present work. For the reaction between AlCl and O2 we find k(T) = 6.8 X 10 to the minus 13th power exp(-2990/T) + 1.5 X 10 to the minus 10th power exp(-10600/T) cc/mol/s, which is compatible with a mechanisms where the Al02 + Cl product channel dominates at lower temperatures, while the OAlCl + O channel dominates at higher temperatures. The ln k(T) versus dependence of the AlCl/O2 reaction is contrasted to those observed for AlO/O2 and BF/02 reactions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 28, 1986
- Accession Number
- ADA174479
Entities
People
- Arthur Fontijn
Organizations
- Rensselaer Polytechnic Institute