Crystallization profile and morphological study of SAPO-5 templated by imidazolium cations of different functional groups

• Main Authors: Auwal, Ismail Alhassan, Mintova, Svetlana, Ling, Tau Chuan, Khoerunnisa, Fitri, Wong, Ka-Lun, Ng, Eng-Poh
• Format: Article
• Published: ELSEVIER 2020
• Subjects: QD Chemistry
• Online Access: http://eprints.um.edu.my/36203/
• Institution: Universiti Malaya

1-Propyl-2,3-dimethyl-1H-imidazole-3-ium (pmIm](+)), 3-(2,3-dihydroxypropyl)-1,2-dimethyl-1H-imidazole-3- ium (dhmIm](+)) and 1-benzyl-2,3-dimethyl-1H-imidazole-3-ium (bzmIm](+)) cations were used as organic templates for crystallizing SAPO-5 with AFI microporous framework. The physico-chemical influences of the functional groups of the templates (e.g. polarity/hydrophilicity, molecular dimension and size) on SAPO-5 formation were investigated. The results revealed that the crystallization rate, crystallinity and solid yield could be enhanced by increasing the polarity/hydrophilicity of the templates. In addition, the isomorphous Si substitution, morphology and particle size of the resulted SAPO-5 were also affected by the substituted groups of the imidazolium templates. The thermogravimetry results further supported that the selection of organic template with proper polarity/hydrophilicity could be crucial to obtain SAPO-5 with high porosity (S-BET, S-mic, S-ext and V-total) as high polar/hydrophilic template exhibited stronger chemical interaction with the AFI framework during template removal process via calcination process.