The reaction of OH with H at elevated temperatures

The temperature dependence of the rate constant for the reaction between OH radicals and H atoms has been determined in Ar-saturated solutions at pH 2. The reaction was studied in the temperature range 5-233 deg. C. The rate constants at 20 deg. C and 200 deg. C are 9.3x109 and 3.3x1010 dm3 mol-1 s-1, respectively. The activation energy was found to be 8.2±0.4 kJ mol-1 (2.0±0.1 kcal mol-1). This value is lower than that expected for a diffusion controlled reaction