Superacid ZrO2-SiO2-SnO2 Mixed Oxide: Synthesis and Study
Date
2021-03-16
Journal Title
Journal ISSN
Volume Title
Publisher
Видавництво Львівської політехніки
Lviv Politechnic Publishing House
Lviv Politechnic Publishing House
Abstract
Суперкислотні потрійні ZrO2 SiO2 SnO2 оксиди (Н0 = –14.52) синтезовано золь-гель методом з атомним співвідношенням в межах: 20 ≤ Zr4+ ≤ 29, 60 ≤ Si4+ ≤ 67, 11 ≤ Sn4+ ≤ 20 %. Суперкислотність ZrO2 SiO2 SnO2 оксиду пояснена формуванням координаційно-ненасичених Zr4+ йонів, як сильних центрів Льюїса
Superacid ternary ZrO2 SiO2 SnO2 oxide has been synthesized by the sol-gel method with a different atomic ratio Zr:Si:Sn. The highest strength of acid sites has been observed in the ranges of 20 ≤ Zr4+ ≤ 29, 60 ≤ Si4+ ≤ 67, 11 ≤ Sn4+ ≤ 20 at.%. According to the XPS spectra and 119Sn, 29Si MAS NMR spectra of ZrO2 SiO2 SnO2 a partial shift of electron density from zirconium to silicon ions was observed resulting in the formation of superacid Lewis sites. It was shown that superacid Zr29Si60Sn11 mixed oxide efficiently catalyzes acylation of toluene with acetic anhydride at 423 K in a flow reactor with 45% conversion of anhydride at 100% selectivity towards p-methylacetophenone.
Superacid ternary ZrO2 SiO2 SnO2 oxide has been synthesized by the sol-gel method with a different atomic ratio Zr:Si:Sn. The highest strength of acid sites has been observed in the ranges of 20 ≤ Zr4+ ≤ 29, 60 ≤ Si4+ ≤ 67, 11 ≤ Sn4+ ≤ 20 at.%. According to the XPS spectra and 119Sn, 29Si MAS NMR spectra of ZrO2 SiO2 SnO2 a partial shift of electron density from zirconium to silicon ions was observed resulting in the formation of superacid Lewis sites. It was shown that superacid Zr29Si60Sn11 mixed oxide efficiently catalyzes acylation of toluene with acetic anhydride at 423 K in a flow reactor with 45% conversion of anhydride at 100% selectivity towards p-methylacetophenone.
Description
Keywords
тверда суперкислота, потрійний оксид, діоксид олова, сила кислотних центрів, центри Льюїса, solid superacid, ternary oxide, tin dioxide, acid strength, Lewis sites
Citation
Superacid ZrO2-SiO2-SnO2 Mixed Oxide: Synthesis and Study / Svitlana Prudius, Natalia Hes, Volodymyr Trachevskiy, Oleg Khyzhun, Volodymyr Brei // Chemistry & Chemical Technology. — Lviv : Lviv Politechnic Publishing House, 2021. — Vol 15. — No 3. — P. 336–342.