Effect of Porous Structure and Acidity of ZSM-5/SBA-15 Catalyst on 1,3,5-Triisopropylbenzene Cracking Catalytic Activity.

ZSM-5/SBA-15 composite materials with different acidities and mesoporous system formations were successfully synthesized by three-step method. The catalysts were characterized by XRD, HR-TEM, BET, EDX and TPD-NH3 methods. It showed that the Si/Al molar ratio had effect on the formation and property of materials. Among synthesized catalysts with the different Si/Al molar ratios of 30 (HZSC-30), 50 (HZSC-50), 70 (HZSC-70), HZSC-50 catalyst had better mesoporous system formation and acidity. These properties helped this catalyst to have higher catalytic activity in 1,3,5-triisopropylbenzene cracking reaction than other studied catalysts in term of higher benzene product yield. In comparison to HZSM-5 microporous material that had the similar Si/Al molar ratio of 50, it showed that the formation of mesopore system of HZSC-50 catalyst had a major improvement on the cracking catalytic activity.

Study on the Synthesis and Characterization of Nano Silver Loaded ZSM-5 Zeolite for Bacterial Elimination.

The synthesis of nano silver coated ZSM-5 zeolite (Ag/ZSM-5) by ion exchange method combined with anaerobic thermal treatment and its bacterial elimination performance were studied. The various Ag content of different samples was analysed by atomic absorption spectroscopy method. The Ag/ZSM-5 sample with 0.251 wt% Ag (denoted as ZAg3) was characterized by using atomic absorption spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and pulsed CO chemisorption methods. The results showed that silver nanoparticles with a small nano-size of 2-3 nm were formed and distributed on the surface of ZSM-5 zeolite with a dispersion value of 59%. The samples denoted as ZAg1, ZAg2, ZAg3, ZAg4 correspond to a Ag content of 0.064; 0.128; 0.251; 0.253 wt% Ag. In the evaluation series, after 10 min of contact time between bacterial and Ag/ZSM-5, over 99% of E.coli (initial concentration was 10(6) cfu/ml) could be eliminated by Ag/ZSM-5 with the Ag content of at least 0.251 wt% (ZAg3). In addition, over 99% of Coliform (initial concentration was 10(5) cfu/ml) could be eliminated by Ag/ZSM-5 with Ag content of at least 0.128 wt% (ZAg2). In a further evaluation series varying the contact time, ZAg3 sample could eliminate over 99% and 100% of Ecoli after 10 min and 60 min, respectively (initial concentrations of both E.coli and Coliform were 10(5) cfu/ml). In addition, it could eliminate 100% of Coliform in only 10 min of contact time.