Abstract
TiO 2 nanorods and ZrO 2-modified TiO 2 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 TiO 2 nanorods with diameters ranging from 20 to 200 nm and with lengths of up to 5 μm were synthesized by a hydrothermal method at 180 °C. ZrO 2 nanoparticles with the diameters ranging from 10 to 20 nm were evenly deposited on TiO 2 nanorods. IR and XPS results suggested that sulfated ZrO 2/TiO 2 nanocomposite has higher content of sulfate groups on the surface with a S/(Zr+Ti) ratio of 13.6% than sulfated TiO 2 nanorods with a S/Ti ratio of 4.9%. The HPLC results showed that sulfated ZrO 2/TiO 2 nanocomposite have enhanced catalytic activity for esterification reaction between levulinic acid and ethanol compared to sulfated TiO 2 nanorods. The conversion of levulinic acid to ethyl levulinate can reach to 90.4% at the reaction temperature of 105 °C after 180 min.
| Original language | English |
|---|---|
| Pages (from-to) | 4499-4505 |
| Number of pages | 7 |
| Journal | ACS Applied Materials and Interfaces |
| Volume | 4 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 26 Sep 2012 |
Keywords
- bio-oil
- levulinic acid
- nanocomposite
- sulfate
- TiO
- ZrO