A Critical Review of the Gas‐Phase Reaction Kinetics of the Hydroxyl Radical

The literature pertinent to reactions of the hydroxyl radical has been reviewed. An extensive discussion is given for reactions of the hydroxyl radical with itself and with CO, H2, and CH4. These four reactions are: (1) OH+OH→H2O+O; (2) CO+OH→CO2+H; (3) H2+OH→H2O+H; (4) CH4+OH→CH3+H2O.Values are recommended for k1 and k2 and for the ratio k3/k2 and k4/k2. These rate ratios are used with the previously established value of k2 to obtain recommended values for k3 and k4.The recommended values in cm3 mol‐1·s‐1, the temperature range, and the uncertainty are: k1=1.55×1012, 300 K, log k±0.1, 05k2=3.1×1011 exp(−300/T), 300−2000 K, log k±.3k3/k2=73 exp(2300/T), 300−2000 K, log k3/k2±.3k3=3.8×1013 exp(−2600/T), 300−2000 K, log k±.3k4/k2=92 exp(2200/T), 300−2000 K, log k3/k2±.3k4=2.85×1013 exp(−2500/T), 300−2000 K, log k±.7. Rate expressions are also recommended for a number of other hydroxyl reactions whose rates are less well established.