Preparation of zinc oxide catalyst with activated carbon support for ozone decomposition

Investigation of catalyst for ozone decomposition was carried out by using zinc oxide (ZnO) catalyst and granular activated carbon (GAC) support. Ozone needs to be decomposed because it is harmful to human and can lead to death. Before GAC was used as a support, GAC was pre-treated using chloride acid (HCl) and sodium hydroxide (NaOH) to remove impurities. ZnO was impregnated onto the surface of GAC by using zinc carbonate (ZnCO₃) solution as precursor and then calcined at 300 °C to decompose carbon dioxide (CO₂). Size of GAC and loading percentage of ZnO were varied to get the highest catalytic activity. Size of GAC was varied between 18 - 100 mesh and loading percentage was between 0 - 2%-w. The morphology, composition, and crystal phase were characterized by BET, SEM-EDX, and XRD method. From XRD method, crystal phase of catalyst was changed from ZnCO₃ structure to ZnO when calcined with exact temperature. Ozone decomposition was performed at room temperature and atmospheric pressure using fixed bed reactor. ZnO/GAC with smallest size (60 - 100 mesh) and highest loading percentage (2%-w) showed the highest activity which the conversion reached 100% for 30 minutes. ZnO/GAC with smallest size and highest loading percentage had the largest surface area and the most active sites to decompose ozone.