TY - JOUR
T1 - Synthesis and characterization of H-ZSM-5 zeolites and their catalytic performance in CH3Br conversion to aromatics
AU - Tao, Ling
AU - Li, Gui Sheng
AU - Yin, Shuang Feng
AU - Qiang, Ou Yang
AU - Luo, Sheng Lian
AU - Zhou, Xiao Ping
AU - Au, Chak Tong
N1 - Funding Information:
Acknowledgments The project was financially supported by Doctoral Program Foundation of Institutions of Higher Education of China (Grant No. 200805320001), the National Natural Science Foundation of China (20873038, J0830415), Opening Fund of State Key Lab of Chemical Resource Engineering (Beijing University of Chemical Technology), Outstanding Young Research Award of National Natural Science Foundation of China (Grant No E50725825), and 863 project from the Ministry of Science and Technology of China (Grant No. 2006BAE02B05). C.T. Au thanks the Hunan University for an adjunct professorship.
PY - 2011/6
Y1 - 2011/6
N2 - Described in this paper are the synthesis, characterization and catalytic application of H-ZSM-5 zeolites for the conversion of CH3Br into aromatics. The H-ZSM-5 zeolites were fabricated by hydrothermal crystallization using n-butylamine (BTA) as a template and characterized by XRD, SEM and NH3-TPD techniques. The effects of batch SiO2/Al2O3 ratio, alkalinity, NaCl/Al2O3 ratio, seed crystals, and crystallization time on the yield, structure/texture and catalytic performance were systematically studied. Adopting the optimum sol (SiO2/Al 2O3 = 70, BTA/SiO2 = 0.2847, Na2O/SiO 2 = 0.1237, H2O/SiO2 = 37.4, NaCl/Al 2O3 = 60, and seed/SiO2 = 5 wt%) and under the most preferable crystallization conditions of 100° C/24 h-170° C/24 h, H-ZSM-5 zeolites of high crystallinity and small size (300-700 nm) were obtained. Good catalytic performance was observed over the H-ZSM-5 zeolites (aromatic yield up to 44.2%). However, unlike the modification of large commercial HZSM-5, the use of MoO3 or PbO as modifying agents for the small-size H-ZSM-5 zeolites results in a decline of catalytic performance. The relationship between the structure and the catalytic efficiency of as-synthesized H-ZSM-5 samples were investigated. It was found that with crystallinity enhancement and/or decline in crystal size, there is improvement of catalytic performance.
AB - Described in this paper are the synthesis, characterization and catalytic application of H-ZSM-5 zeolites for the conversion of CH3Br into aromatics. The H-ZSM-5 zeolites were fabricated by hydrothermal crystallization using n-butylamine (BTA) as a template and characterized by XRD, SEM and NH3-TPD techniques. The effects of batch SiO2/Al2O3 ratio, alkalinity, NaCl/Al2O3 ratio, seed crystals, and crystallization time on the yield, structure/texture and catalytic performance were systematically studied. Adopting the optimum sol (SiO2/Al 2O3 = 70, BTA/SiO2 = 0.2847, Na2O/SiO 2 = 0.1237, H2O/SiO2 = 37.4, NaCl/Al 2O3 = 60, and seed/SiO2 = 5 wt%) and under the most preferable crystallization conditions of 100° C/24 h-170° C/24 h, H-ZSM-5 zeolites of high crystallinity and small size (300-700 nm) were obtained. Good catalytic performance was observed over the H-ZSM-5 zeolites (aromatic yield up to 44.2%). However, unlike the modification of large commercial HZSM-5, the use of MoO3 or PbO as modifying agents for the small-size H-ZSM-5 zeolites results in a decline of catalytic performance. The relationship between the structure and the catalytic efficiency of as-synthesized H-ZSM-5 samples were investigated. It was found that with crystallinity enhancement and/or decline in crystal size, there is improvement of catalytic performance.
KW - Acid catalyst
KW - Aromatic hydrocarbon
KW - Methyl bromide
KW - ZSM-5 zeolite
UR - http://www.scopus.com/inward/record.url?scp=79960074607&partnerID=8YFLogxK
U2 - 10.1007/s11144-011-0292-5
DO - 10.1007/s11144-011-0292-5
M3 - Journal article
AN - SCOPUS:79960074607
SN - 1878-5190
VL - 103
SP - 191
EP - 207
JO - Reaction Kinetics, Mechanisms and Catalysis
JF - Reaction Kinetics, Mechanisms and Catalysis
IS - 1
ER -