Investigation the effects of Al-grafting and calcination temperature on acidity and physicochemical properties of silica SBA-15
Autor: | Mehdi Rashidzadeh, Sepehr Sadighi, Akbar Irandoukht, Reza Orouj |
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Jazyk: | angličtina |
Rok vydání: | 2020 |
Předmět: |
Mole ratio
Materials science Hexagonal crystal system chemistry.chemical_element High aluminum General Chemistry physicochemical properties Grafting law.invention lcsh:Chemistry Chemical engineering chemistry lcsh:QD1-999 law Aluminium silica sba-15 post-synthesis al-grafting Calcination Fourier transform infrared spectroscopy Mesoporous material acidity |
Zdroj: | Journal of the Serbian Chemical Society, Vol 85, Iss 10, Pp 1345-1356 (2020) |
ISSN: | 1820-7421 0352-5139 |
Popis: | In this study, the effect of calcination temperature and Si/Al mole ratio on acidity and physicochemical properties of silica SBA-15 were investigated. Silica SBA-15 samples were calcined at 350, 450 and 550?C, and then post-synthesis, the Al-grafting method was applied to incorporate aluminum species into their framework with Si/Al mole ratio of 10 and 30. Characterizations using small angle XRD and N2 adsorption?desorption techniques indicated that the hexagonal mesoporous structure was retained after performing Al-grafting even at the high aluminum loading. Moreover, FTIR results implied that the aluminum species were incorporated into the SBA-15 framework. NH3-TPD results showed that by decreasing Si/Al mole ratio at all calcination temperatures, the number of weak acid sites increased in comparison to those of the pure SBA-15 samples. Additionally, the maximum total acidity of synthesized samples was observed at the calcination temperature of 450?C with Si/Al mole ratio of 30. |
Databáze: | OpenAIRE |
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