Abatement of toluene from polluted air over Mn/Clinoptilolite–CeO2 nanopowder: Impregnation vs. ultrasound assisted synthesis with various Mn-loading

• Employing of clinoptilolite in synthesis of Mn/Clinoptilolite–CeO2 nanocatalyst.
• Superior properties of acid treated clinoptilolite in catalyst synthesis.
• Superior activity of sonochemically synthesized Mn/Clinoptilolite–CeO2 nanocatalyst.
• Optimum effect of Mn addition in Mn/Clinoptilolite–CeO2 nanocatalyst synthesis.
• Successful employing of Mn/Clinoptilolite–CeO2 nanocatalyst in VOC abatement.

Total oxidation of toluene over Mn(5%, 10%, 15%)/Clinoptilolite–CeO2 nanocatalysts was performed. Mn was doped via two different methods of impregnation and sonochemistry. The catalysts were characterized by XRD, FESEM, EDX, BET and FTIR analyses. The physicochemical characterizations showed superior properties of sonochemically synthesised nanocatalysts like homogenous morphology, small and dispersed particles, and strong interaction. Addition of CeO2 as a promoter to acid-treated clinoptilolite remarkably increased catalytic activity. XRD analysis demonstrated acid treatment of clinoptilolite induces noticeable decrease in crystals size and their crystallinity, while the specific surface area increased. Furthermore, no obvious peaks related to MnOx were found in XRD patterns even at high loadings of Mn which might be attributed to the high dispersion of particles in sonochemistry method. Due to the effect of sonication power, even at high loadings of Mn(15%), the morphology of the catalyst was agglomeration free and surface area was high. Comparison of catalytic activity of sonochemically and impregnated Mn(5%)/Clinoptilolite–CeO2 nanocatalyst showed that sonochemically synthesized catalyst can oxidize toluene 5–10% more than impregnated one at all temperature ranges. Increasing metal content enhanced the catalytic activity.

Total oxidation of toluene over a series of Clinoptilolite–CeO2 supported Mn nanocatalysts (5%, 10% and 15%) has been investigated. Nanocatalysts were synthesized via ultrasound assisted and impregnation methods. The synthesized nanocatalysts were characterized by XRD, FESEM, EDX, BET and FTIR analyses. The results showed that sonochemistry could remarkably improve the catalytic properties. With sonochemistry higher levels of Mn could efficiently load on the support with high surface area, without formation of particles agglomeration in comparison to impregnation method. The Mn(15%)/Clinoptilolite–CeO2 was observed to be the most active catalyst which is contributed to well-dispersed Mn particles with high surface area.Figure optionsDownload as PowerPoint slide