Abstract
Various zirconia content in ZrO
2
–TiO
2
mixed oxide catalysts (x = 5, 10, 20 ZrO
2
wt%) were synthesized by cost-effective sol–gel process and characterized by different techniques, i.e. XRD diffraction patterns, TG–DTA analyses, FTIR spectroscopy, N
2
adsorption/desorption measurements, and TEM microscope. The investigation of the acidic/basic properties was studied by means of FTIR spectroscopy using pyridine as an adsorbed molecule. Characterization estimates exhibit that the deposition by ZrO
2
improves the surface properties of TiO
2
structures and increase the TiO
2
surface area up to 92 m
2
/g. TEM results affirmed the homogeneous distribution of ZrO
2
particles on the surface of TiO
2
of particle size in the range of 12–17 nm. The performance of the prepared zirconia–titania catalysts with different concentration ratios in acridine derivates synthesis from hydroxyl-benzaldehyde was studied. The results of catalytic test reveal that, the activity of ZrO
2
–TiO
2
catalysts was significantly enhanced by depositing an optimum amount ratio of ZrO
2
reach to 10 % to raise the yield to 95, 97 and 99 %. This can be attributed to the higher its surface area and its performance as basic site catalyst in the studied test.
Graphical Abstract