Temperature dependence for the absolute rate constant for the reaction CH/sub 2/OH + O/sub 2/. -->. HO/sub 2/ + H/sub 2/CO from 215 to 300 K

Journal Article · Thu Jul 14 00:00:00 EDT 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100325a008· OSTI ID:6289595

Nesbitt, F L; Payne, W A; Stief, L J

The absolute rate constant for the reaction CH/sub 2/OH + O/sub 2/ ..-->.. HO/sub 2/ + H/sub 2/CO has been determined from 215 to 300 K in a discharge flow system at 1-Torr pressure. The decay of CH/sub 2/OH was monitored in excess O/sub 2/ by collision-free sampling mass spectrometry. The temperature dependence observed is quite different from the usual Arrhenius form. For the 215-250 K interval, an activation energy of 3.4 kcal/mol is obtained. Above 250 K, the rate constant increases at a slower rate; previous high-temperature studies (1000-2000 K) again show a faster increase in the rate constant. A possible explanation for these observations is that the reaction mechanism changes from addition at low temperature to direct abstraction at high temperatures.

• Research Organization: NASA/Goddard Space Flight Center, Greenbelt, MD (USA)
• OSTI ID: 6289595
• Journal Information: J. Phys. Chem.; (United States), Vol. 92:14
• Country of Publication: United States
• Language: English

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