Catalytic decomposition of ozone in air

Abstract

The catalytic decomposition of ozone was investigated by using a tubular fixed‐bed reactor. The performance tests and reaction kinetic studies were conducted for two catalysts, i.e., MnO₂ and Pt/γ ‐Al₂O₃ (symbolized as Dash‐220). The experiments were carried out at various constant reaction temperatures (288–338 K) and space velocities (24,000 ‐ 68,000 hr⁻¹). The decomposition efficiencies of ozone with values higher than 99 % can be achieved at low temperatures (e.g., 338 K) and moderate space velocities (e.g., 38,000 hr⁻¹). The results indicated that the Dash‐220 catalyst gave higher decomposition performance than MnO₂ catalyst at the same reaction conditions. For the reaction kinetics, it was found that the pseudo‐first‐order chemical reaction kinetic equation was appropriate for the catalytic decomposition of ozone investigated in this study. The apparent activation energies for MnO₂ and Dash‐220 catalysts are 53.2 and 51.1 kJ mol⁻¹, respectively. The corresponding pre‐exponential factors are 1,863 and 3,681 mol (s g‐cat. (mol m⁻³))⁻¹, respectively.

Key words:

• Ozone
• catalytic decomposition
• manganese dioxide
• platinum/γ‐Al₂O₃