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    ABSTRACT Background For removing toluene as a representative of volatile organic compounds (VOCs) from waste gas stream, a catalytic oxidation was utilized over Cu/Clinoptilolite-CeO2. The nanocatalyst with different loadings of Cu(5, 10,... more
    ABSTRACT Background For removing toluene as a representative of volatile organic compounds (VOCs) from waste gas stream, a catalytic oxidation was utilized over Cu/Clinoptilolite-CeO2. The nanocatalyst with different loadings of Cu(5, 10, 15 wt.%) was sonochemically synthesized and its performance was studied. Characterization techniques of XRD, FESEM, BET, EDX and FTIR were applied.ResultsXRD results indicated well- dispersed small copper particles even at high loadings of copper. While non-sonicated Cu/Clinoptilolite-CeO2 catalyst showed agglomerated, non-uniform morphology, small particles with uniform shape and size with different degrees of agglomeration was observed in sonicated Cu/Clinoptilolite-CeO2 catalyst. A narrow particle size distribution with average size of 21 nm was observed in sonicated sample. BET analysis demonstrated considerable effects of HCl treatment in increasing the specific surface area of clinoptilolite. Also, it showed great influence of CeO2 addition as a promoter that sharply enhances the surface area to 71.7 m2/g.Conclusion Catalytic performance tests revealed that Cu(15%)/Clinoptilolite-CeO2 synthesized with ultrasound had the best performance of about 98% toluene abatement even at high concentration of toluene (3000 ppm). The stability test of synthesized nanocatalyst confirmed constant activity of the nanocatalyst for about 1440 minutes which makes it the promising catalyst for removal of VOCs.
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    ABSTRACT In this research nanocatalysts containing 5, 10 and 15 wt.% of Ni, dispersed by sonication over CeO2–clinoptilolite composite support were compared toward total oxidation of toluene. Their catalytic performance at different... more
    ABSTRACT In this research nanocatalysts containing 5, 10 and 15 wt.% of Ni, dispersed by sonication over CeO2–clinoptilolite composite support were compared toward total oxidation of toluene. Their catalytic performance at different temperatures between 150 and 350 °C was studied based on the oxidative destruction of toluene. The results indicated that the activity of Ni/CeO2–clinoptilolite nanocatalyst for toluene oxidation increased from 33 to 44% at 250 °C by employing sonochemical method in synthesis of catalyst. Meanwhile, the catalytic activity was also improved when Ni content was increased from 5 to 10 and 15 wt.%. With the aid of several characterization techniques like XRD, FESEM, PSD, EDX, BET and FTIR, the correlation between nanocatalyst structure and its activity was addressed. It is indicated that sonochemical method can lift the catalytic activity due to the better dispersion of catalyst active components and also higher surface area. Among sonicated samples, 15 wt.% Ni nanocatalyst showed the highest toluene oxidation due to the better dispersion of catalyst active components and hence to more effective catalytic sites.
    BACKGROUND: To remove toluene (a representative volatile organic compound (VOC)) from a waste gas stream, catalytic oxidation was utilized over Cu/Clinoptilolite–CeO2 nanocatalyst. The nanocatalyst with different loadings of Cu (5, 10,... more
    BACKGROUND: To remove toluene (a representative volatile organic compound (VOC)) from a waste gas stream, catalytic
    oxidation was utilized over Cu/Clinoptilolite–CeO2 nanocatalyst. The nanocatalyst with different loadings of Cu (5, 10, 15wt%)
    was sonochemically synthesized and its performance in catalytic oxidation of toluene was studied. Characterization by XRD,
    FESEM, BET, EDX and FTIR were applied.
    RESULTS: XRD results indicated well-dispersed small copper particles even at high loadings of copper. Non-sonicated
    Cu/Clinoptilolite–CeO2 catalyst showed agglomerated, non-uniformmorphology,while small particleswith uniformshape and
    sizewith different degrees of agglomerationwere observed in sonicated Cu/Clinoptilolite–CeO2 catalyst. A narrowparticle size
    distribution with average size 21 nm was observed in the sonicated sample. BET analysis demonstrated considerable effects of
    HCl treatment in increasing the specific surface area of clinoptilolite. It also showed the strong influence of CeO2 addition as a
    promoter that sharply enhanced the surface area to 71.7m2 g−1.
    CONCLUSION: Catalytic performance tests revealed that Cu(15%)/Clinoptilolite–CeO2 synthesized with ultrasound had the
    best performance of about 98% toluene abatement even at high concentrations of toluene (3000 ppm). A stability test of the
    synthesized nanocatalyst confirmed its constant activity for 1440min,making it a promising catalyst for removal of VOCs.
    © 2014 Society of Chemical Industry
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