The Photocatalytic Activity of Zeolite/TiO2 Composite for Esterification Reaction of Kapok Seed (Ceiba pentandra) Oil
DOI: https://doi.org/10.55373/mjchem.v25i1.64
Keywords: Natural zeolite; titanium dioxide; bifunctional catalyst; esterification; biodiesel
Abstract
In this paper, we report on the preparation of a composite based on natural zeolite and titanium dioxide (TiO2). This composite can act as a bifunctional catalyst for the esterification reaction of kapok seed (Ceiba pentandra) oil. TiO2, which exists as a combination of 90% anatase and 10% rutile, played the role of photocatalyst, while zeolite was the catalyst. The zeolite/TiO2 composite was obtained by the hydrothermal method. A preliminary analysis of its structure carried out using XRD showed that the addition of TiO2 did not change the structures of TiO2 or zeolite. SEM/EDX characterization was performed to determine the distribution of Ti on the surface of the zeolite. The EDX and SEM results confirmed that TiO2 was successfully loaded onto the surface of natural zeolite. The methylene blue method was used with UV-Vis spectrophotometry to determine the surface area of the composite. A value of 20.866 m2 g-1 was obtained, which indicated that the composite was a good catalyst. The band gap energy of the composite catalyst was 3.0132 eV, which confirmed the presence of TiO2. The photocatalyst allowed the esterification reaction of kapok seed oil to proceed at 35 °C under UV irradiation. This reaction led to biodiesel conversion. The chemical characteristics of the biodiesel produced were confirmed by GC-MS. Biodiesel properties such as kinematic viscosity, density, flash point and smoke point were determined. The results of the analyses showed that the biodiesel produced met all the specifications of the ASTM D6751 and ASTM D445 biodiesel standards. As a result, the composite zeolite/TiO2 has good potential as a catalyst for biodiesel conversion.