| Popis: |
Laser-induced fluorescence is used to measure OH radical desorption from Pt foils in oxidation of H 2 CH 4 , C 3 H 6 and NH 3 with O 2 at partial pressures of ≈ 0.1 Torr and surface temperatures between 1000 and 1600 K. The peak OH production ratios are approximately 12:8:3:1 for these fuels. The maximum OH production occurs in excess O 2 except for CH 4 where the lower sticking coefficient of CH 4 produces a maximum near the stoichiometric composition. The variation between fuels is interpreted in terms of different sticking coefficients of the fuels, competition of adsorbed C or N with H for oxygen, and possibly by double abstraction reactions which do not produce an OH surface intermediate. Ammonia produced much less OH than the other fuels, and this appears to indicate mechanisms in which OH is not a significant intermediate. |
