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

BACKGROUND: To remove toluene (a representative volatile organic compound (VOC)) from a waste gas stream, catalytic oxidation was utilized over Cu/Clinoptilolite-CeO 2 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. RESULTS: XRD results indicated well-dispersed small copper particles even at high loadings of copper. Non-sonicatedCu/Clinoptilolite-CeO 2 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-CeO 2 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 CeO 2 addition as a promoter that sharply enhanced the surface area to 71.7 m 2 g −1 .CONCLUSION: Catalytic performance tests revealed that Cu(15%)/Clinoptilolite-CeO 2 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. Effect of Cu-loadingThe effect of Cu loading on the activity of synthesized clinoptilolite, clinoptilolite-CeO 2 , and Cu(5%-10%-15%)/Clinoptilolite-CeO 2 , was investigated over the temperature range of 150-350 ∘ C J Chem Technol Biotechnol 2015; 90: 765-774

Beneficial Use of Ultrasound in Rapid-Synthesis of SAPO34/ZSM-5 Nanocomposite and Its Catalytic Performances on MTO Reaction

“…It could be expected that during this process, ZSM-5 cores are dissolved and act as a nutrient for the growth of U-SAPO-34 zeolite in the shell. Suitable nucleation sites and controlled crystal growth in ultrasonic assisted hydrothermal procedure facilitate the formation of the U-SAPO-34 in small size ranges. − Using ultrasonic wave at this stage leads to rapid homogeneity in the dispersion of the initial nuclei. Moreover, sonochemical cavitation during the ultrasonic process assists the composite growth by local increase of temperature and pressure in the gel.…”

Aktivasi Zeolit Alam Sebagai Adsorben Pewarna Alami Kulit Buah Naga (Pitaya)

“…Aktivasi zeolit alam dilakukan secara kimia dan fisika, pada aktivasi kimia zeolit yag telah dipreparasi dilarutkan dengan asam klorida 3M. Proses aktivasi kimia bertujuan untuk menghilangkan pengotor yang menepel pada zeolit sehingga pori-pori zeolit semakin besar dan meningkatan rasio Si/Al diikuti dengan meningkatnya adsorptivitas karena pelepasan Al dari sisi aktif Si-O-Al menjadi Si-O-Si [13].…”

Utilisation of waste Cu-, Mn- and Fe-loaded zeolites generated after wastewater treatment as catalysts for air treatment

“…In most of the studies the metal loading was optimized to obtain highly active metal-oxo-species on zeolite support. The tested systems were single metal oxides (Mn, Co., Fe, Cu) supported on clinoptilolite (Ozcelik et al, 2009;Soylu et al, 2010;Russo et al, 2018a;Russo et al, 2018b), bimetal oxides (Mn/Ni, Fe/Cu) supported on clinoptilolite (Ahmadi et al, 2017;Rostami and Jonidi Jafari, 2014) and single metals (Mn, Cu, Ni) supported on CeO 2 -clinoptilolite systems (Yosefi et al, 2015a;Yosefi et al, 2015b;Yosefi et al, 2015c). The catalysts prepared by incipient wetness impregnation of clinoptilolite in hydrogen form, which resulted in 9.5% MnO 2 on clinoptilolite, exhibited the highest performance among different oxides in comparison with Fe, Cu and Co-oxides on the same support (Soylu et al, 2010).…”