TY - JOUR
T1 - Methylation of 2-methylnaphthalene with methanol to 2,6-dimethylnaphthalene over HZSM-5 modified by NH4F and SrO
AU - Zhang, Chen
AU - Guo, Xin Wen
AU - Wang, Ya Nan
AU - Wang, Xiang Sheng
AU - Song, Chun Shan
N1 - Funding Information:
The project was supported by Program for New Century Excellent Talents in University (no. NCET-04-0268) and by the 111 Project.
Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 2007/10
Y1 - 2007/10
N2 - The methylation of 2-methylnaphthalene (2-MN) into 2,6-dimethylnaphthalene (2,6-DMN) was investigated over the solid acid catalysts. The results show that HZSM-5 modified by NH4F has better catalytic performance than parent HZSM-5 due to the decrease in the acidity. When NH4F/HZSM-5 is further modified by SrO, its catalytic activity decreases due to the decrease in the total acid amount and acidic strength. As a result, the comprehensive modification of NH4F and SrO leads to the increase in the 2,6-DMN selectivity (2,6-DMN to DMN), up to 64.8% when 2-MN conversion is 10%. We calculated the ESP charge by density functional theory and the results show that the 6-position in 2-MN has higher ESP charge value than 7-position. The formation of 2,6-DMN is favored energetically as compared to that for 2,7-DMN. This suggests during the alkylation of 2-MN inside the ZSM-5 channel, the formation of 2,6-DMN is favored electronically than that of 2,7-DMN. Hence, lowering the acidity of catalyst is a key factor to obtain high selectivity of 2,6-DMN.
AB - The methylation of 2-methylnaphthalene (2-MN) into 2,6-dimethylnaphthalene (2,6-DMN) was investigated over the solid acid catalysts. The results show that HZSM-5 modified by NH4F has better catalytic performance than parent HZSM-5 due to the decrease in the acidity. When NH4F/HZSM-5 is further modified by SrO, its catalytic activity decreases due to the decrease in the total acid amount and acidic strength. As a result, the comprehensive modification of NH4F and SrO leads to the increase in the 2,6-DMN selectivity (2,6-DMN to DMN), up to 64.8% when 2-MN conversion is 10%. We calculated the ESP charge by density functional theory and the results show that the 6-position in 2-MN has higher ESP charge value than 7-position. The formation of 2,6-DMN is favored energetically as compared to that for 2,7-DMN. This suggests during the alkylation of 2-MN inside the ZSM-5 channel, the formation of 2,6-DMN is favored electronically than that of 2,7-DMN. Hence, lowering the acidity of catalyst is a key factor to obtain high selectivity of 2,6-DMN.
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U2 - 10.1016/j.cclet.2007.07.025
DO - 10.1016/j.cclet.2007.07.025
M3 - Article
AN - SCOPUS:34848830449
SN - 1001-8417
VL - 18
SP - 1281
EP - 1284
JO - Chinese Chemical Letters
JF - Chinese Chemical Letters
IS - 10
ER -