Synthesis and Characterization of Sulfated TiO2 Nanorods and ZrO2/TiO2 Nanocomposites for the Esterification of Biobased Organic Acid

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• 作者：Zhonglai Li ; Renata Wnetrzak ; Witold Kwapinski ; James J. Leahy
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2012
• 出版时间：September 26, 2012
• 年：2012
• 卷：4
• 期：9
• 页码：4499-4505
• 全文大小：454K
• 年卷期：v.4,no.9(September 26, 2012)
• ISSN：1944-8252

文摘

TiO₂ nanorods and ZrO₂-modified TiO₂ nanocomposites have been prepared by hydrothermal synthesis and the deposition-precipitation method. Their sulfated products were tested as solid superacid catalysts for the esterification of levulinic acid which was used as a model bio-oil molecule. SEM and TEM characterization showed that TiO₂ nanorods with diameters ranging from 20 to 200 nm and with lengths of up to 5 渭m were synthesized by a hydrothermal method at 180 掳C. ZrO₂ nanoparticles with the diameters ranging from 10 to 20 nm were evenly deposited on TiO₂ nanorods. IR and XPS results suggested that sulfated ZrO₂/TiO₂ nanocomposite has higher content of sulfate groups on the surface with a S/(Zr+Ti) ratio of 13.6% than sulfated TiO₂ nanorods with a S/Ti ratio of 4.9%. The HPLC results showed that sulfated ZrO₂/TiO₂ nanocomposite have enhanced catalytic activity for esterification reaction between levulinic acid and ethanol compared to sulfated TiO₂ nanorods. The conversion of levulinic acid to ethyl levulinate can reach to 90.4% at the reaction temperature of 105 掳C after 180 min.

Keywords:

ZrO₂; TiO₂; nanocomposite; sulfate; bio-oil; levulinic acid