ZnAl₂O₄/SiO₂ as an Efficient Nanocatalyst for Esterification of Phthalic Anhydride by 2-Ethylhexanol

In this research, ZnAl₂O₄/SiO₂ as nanocatalyst was produced via modified sol–gel procedure. The X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR) were performed to confirm the structure of nanocatalyst. The particle size was around 14 nm. Moreover, esterification of phthalic anhydride by 2-ethylhexanol was done in the presence of catalytic amounts of ZnAl₂O₄/SiO₂. This heterogeneous nanocatalyst was used repeatedly, but its catalytic activity did not significantly decrease. The yield of this reaction in the presence of ZnAl₂O₄/SiO₂ as nanocatalyst was about 99.2% under the optimized conditions in 45 min of reaction time. These results show that the synthesized nanocatalyst via this method was more efficient.