Synthesis and characterization of sulfated TiO2 nanorods and ZrO2/TiO2 nanocomposites for the esterification of biobased organic acid.
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.
Chemical and Environmental Science, University of Limerick, Ireland.
Zhonglai
Z
Li
Renata
R
Wnetrzak
Witold
W
Kwapinski
James J
JJ
Leahy
D002384:Catalysis; D004951:Esterification; D000431:Ethanol / Q000737:chemistry; D007982:Levulinic Acids / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry*; D013696:Temperature; D014025:Titanium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
D007982:Levulinic Acids; C009495:titanium dioxide; D000431:Ethanol; D015040:Zirconium; D014025:Titanium; C032246:levulinic acid; C028541:zirconium oxide