ZnAl 2 O 4 /SiO 2 as an Efficient Nanocatalyst for Esterification of Phthalic Anhydride by 2-Ethylhexanol
- PDF / 862,351 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 36 Downloads / 171 Views
(0123456789().,-volV)(0123456789().,-volV)
RESEARCH PAPER
ZnAl2O4/SiO2 as an Efficient Nanocatalyst for Esterification of Phthalic Anhydride by 2-Ethylhexanol Soodabe Gharibe1 Received: 21 January 2020 / Accepted: 26 May 2020 Ó Shiraz University 2020
Abstract 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. Keywords Nanocomposite Sol–gel method Heterogeneous catalyst Esterification
1 Introduction The esterification reactions are chiefly used in pharmaceutical, perfumery and polymer industries. The phthalate esters such as dioctyl phthalate, diisoamyl phthalate and dibutyl phthalate are the key plasticizers for polymers covering more than 70% of the plasticizer market worldwide. They are especially applied in the polymerization of olefins particularly vinyl chloride, ethylene and propylene (Villardia et al. 2017; Norddin et al. 2017; Wang et al. 2017a; Soltani et al. 2016; Wang et al. 2013; Gok et al. 2010; Iranpoor et al. 2008). To produce the phthalate esters, the reaction of phthalic anhydride was used either by proper alcohol in the liquid phase with a monoester as intermediate or by a direct route. A large number of acidic catalysts that have been reported for esterification reactions are sulfuric acid, hydrochloric acid, phosphoric acid, ptoluene sulfonic acid and methane sulfonic acid. However, using of these catalysts leads to the formation of colored by-products. In addition, the catalysts could not be recovered and reused by this procedure. Tetrabutyl titanate and & Soodabe Gharibe [email protected] 1
Department of Science, Firoozkooh Branch, Islamic Azad University, Firoozkooh, Iran
tetrabutyl zirconate could be used as catalysts for generation of the phthalate esters, but these catalysts are also not easily recoverable. Thus, the ecologically dangerous homogeneous solid acid is required that could be substituted for to synthesize various phthalate esters. The solid acid catalysts outperform mineral acids because of their features such as noncorrosiveness, high selectivity, high catalytic activity, easy recovery of catalysts and decreased generated amount of harmful wastes (Zhao et al. 2019; Kim et al. 2018; Miao et al. 2018; Wang et al. 2017a, b; Hashemzehi et al. 2017; Patil et al. 2010). For this reason, various solid catalysts for
Data Loading...
