TY - JOUR
T1 - Syntheses of SSZ-39 and mordenite zeolites with N,N-dialkyl-2,6-dimethyl-piperidinium hydroxide/iodides
T2 - Phase-selective syntheses with anions
AU - Bhadra, Biswa Nath
AU - Seo, Pill Won
AU - Jun, Jong Won
AU - Jeong, Jong Hwa
AU - Kim, Tae Wan
AU - Kim, Chul Ung
AU - Jhung, Sung Hwa
N1 - Publisher Copyright:
© 2016 Elsevier Inc.
PY - 2016/11/15
Y1 - 2016/11/15
N2 - SSZ-39 and mordenite zeolites were obtained from the conversion of zeolite Y in the presence of the same reaction precursors (organic templates, NaOH, water, etc.) under a wide range of reaction conditions. The applied templates were N,N-dialkyl-2,6-dimethyl-piperidinium-OH and -I (alkyl: ethyl or methyl). Curiously, SSZ-39 and mordenite were obtained from hydroxides and iodides, respectively, showing firstly the importance of the anion in the selective crystallization of zeolites. Reactions were also performed at the same set of pH values (achieved by adding small amounts of NaOH to the iodide-based precursors) to investigate the effect of basicity; the results did not vary appreciably with the pH of the synthesis precursors. Based on the phase conversion (MOR – > AEI or ANA with increasing reaction time and pH), the selective formation of SSZ-39 and mordenite from hydroxides and iodides, respectively, could be explained in terms of zeolite-promoting and -preventing anions (hydroxide and iodide, respectively). The phase conversion of zeolites could be explained on the basis of the maximum pore size of zeolites, rather than the framework densities. The obtained zeolites (SSZ-39 and mordenite), in their protonated forms, were employed in ethanol dehydration and direct ethylene-to-propylene conversion, and the results showed that the two zeolites have potential application in acid catalysis. In particular, the SSZ-39 with an AEI structure can be applied in the direct production of propylene from ethylene or ethanol.
AB - SSZ-39 and mordenite zeolites were obtained from the conversion of zeolite Y in the presence of the same reaction precursors (organic templates, NaOH, water, etc.) under a wide range of reaction conditions. The applied templates were N,N-dialkyl-2,6-dimethyl-piperidinium-OH and -I (alkyl: ethyl or methyl). Curiously, SSZ-39 and mordenite were obtained from hydroxides and iodides, respectively, showing firstly the importance of the anion in the selective crystallization of zeolites. Reactions were also performed at the same set of pH values (achieved by adding small amounts of NaOH to the iodide-based precursors) to investigate the effect of basicity; the results did not vary appreciably with the pH of the synthesis precursors. Based on the phase conversion (MOR – > AEI or ANA with increasing reaction time and pH), the selective formation of SSZ-39 and mordenite from hydroxides and iodides, respectively, could be explained in terms of zeolite-promoting and -preventing anions (hydroxide and iodide, respectively). The phase conversion of zeolites could be explained on the basis of the maximum pore size of zeolites, rather than the framework densities. The obtained zeolites (SSZ-39 and mordenite), in their protonated forms, were employed in ethanol dehydration and direct ethylene-to-propylene conversion, and the results showed that the two zeolites have potential application in acid catalysis. In particular, the SSZ-39 with an AEI structure can be applied in the direct production of propylene from ethylene or ethanol.
KW - AEI zeolite
KW - Anion effect
KW - Ethylene-to-propylene
KW - Phase-selectivity
KW - SSZ-39
UR - http://www.scopus.com/inward/record.url?scp=84981727007&partnerID=8YFLogxK
U2 - 10.1016/j.micromeso.2016.08.003
DO - 10.1016/j.micromeso.2016.08.003
M3 - Article
AN - SCOPUS:84981727007
SN - 1387-1811
VL - 235
SP - 135
EP - 142
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
ER -