In this study, we examined the experimental catalytic oxidation of gaseous monochlorobenzene (MCBz) with O(3) over Fe(2)O(3) in a packed bed reactor to investigate the feasibility of economical low temperature decomposition at a high space velocity (SV). We investigated the effects of several reaction parameters (temperature, O(3) concentration, and SV) on the MCBz oxidation. At 150 degrees C, the conversion of MCBz over Fe(2)O(3) in the absence of O(3) was only 3%; it increased to 91% over Fe(2)O(3) in the presence of 1200 ppm of 03 at a high SV of 83 s(-1). A long-term operation study revealed that the conversion of MCBz was stable for more than 96 h. In the steady state, the carbon and chlorine balances were 88% and 86%, respectively. Applying a Langmuir-Hinshelwood kinetic model, we estimated an activation energy of 16.7 kJ mol(-1) for MCBz oxidation over Fe(2)O(3) in the presence of O(3). (C) 2011 Elsevier Ltd. All rights reserved.