dc.description.abstract | Various types of volatile organic pollutants (VOCs) are used in industrial processes. Due to their physical and chemical properties, VOCs can easily evaporate during the manufacturing or processing, resulting in fugitive emissions. VOCs are not only present in various industries, but are also important indicators for assessing indoor air quality. Toluene is a typical organic compound that is often used as a cleaning agent for equipment components. Prolonged exposure to poor air quality can lead to symptoms such as dizziness, fatigue, and mood swings. In this study, we developed a novel triple perovskite-type catalyst and investigated the feasibility of adding ammonia and applying catalyst surface modification to further enhance the catalytic activity of the catalysts in the preparation process. The main emphasis of this study includes two parts, one is the application of triple perovskite-type catalyst in thermal catalytic system, and the other is the application of ozone catalytic oxidation (OZCO) for toluene removal using catalyst combined with ozone technology. The results showed that triple perovskite-type catalysts developed were highly active for toluene removal, especially La3MnCuNiO9(n,k) catalyst. In the thermal catalytic system ([C7H8] = 500 ppm), the conversion and mineralization rates of C7H8 at 250°C reached 100% and 83%, respectively. In the ozone catalytic oxidation system ([C7H8] = 20 ppm, O3/C7H8=8; room temperature), the conversion efficiency was maintained at 100% for 6 hours, and the mineralization rate was maintained at a high rate for 4 hours, and gradually decreased to 85% after 5 hours of reaction. The physical and chemical analysis of the catalyst showed that La3MnCuNiO9(n,k) has a high specific surface area and pore volume of 26.74 m2/g and 0.16 cm3/g, respectively. Catalysts with high ratios of Oabs/(Oabs+Olat), Mn4+/(Mn4++Mn3+) and Cu2+ as well as multivalent Ni enhance the catalytic activity which in turn promotes oxidation of toluene. The main products of ozone catalytic oxidation are CO2 and H2O(g), and the removal mechanism is mainly via the decomposition of O3 on the surface of triple perovskite-type catalyst into reactive oxygen species (O*, O2*) with strong oxidizing ability. In the ozone catalytic reaction process, active oxygen generated facilitate the oxidation of toluene at room temperature. The results obtained indicate that this catalyst has great potential for industrial waste gas treatment and indoor air applications. | en_US |