The beneficial use of HCl‐activated natural zeolite in ultrasound assisted synthesis of Cu/clinoptilolite–CeO2 nanocatalyst used for catalytic oxidation of diluted toluene in air at low temperature

Abstract

AbstractBACKGROUNDTo 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, 15 wt%) was sonochemically synthesized and its performance in catalytic oxidation of toluene was studied. Characterization by XRD, FESEM, BET, EDX and FTIR were applied.RESULTSXRD results indicated well‐dispersed small copper particles even at high loadings of copper. Non‐sonicated Cu/Clinoptilolite–CeO2 catalyst showed agglomerated, non‐uniform morphology, while small particles with uniform shape and size with different degrees of agglomeration were observed in sonicated Cu/Clinoptilolite–CeO2 catalyst. A narrow particle 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 71.7 m2 g−1.CONCLUSIONCatalytic 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 1440 min, making it a promising catalyst for removal of VOCs. © 2014 Society of Chemical Industry