Synthesis of Silicotungstic Acid/Ni-Zr-O Composite Nanoparticle by Using Bimetallic Ni-Zr MOF for Fatty Acid Esterification

Abstract

In this study, the bimetallic Ni-Zr MOF-derived nickel-zirconium oxide (Ni-Zr-O)-impregnated silicotungstic acid (HSiW) nanocomposite catalyst (HSiW@Ni-Zr-O) was prepared via a hydrothermal procedure followed by a pyrolysis treatment, and its structural, morphological, and surface components and oxidation states were characterized by using XRD, FTIR, TPD-NH3, SEM, TEM, N2 physisorption, and XPS analyses. Then, the nanocomposite catalysts were successfully applied to the esterification of oleic acid (OA) with methanol. According to its characteristics, the obtained HSiW@Ni-Zr-O-1 catalyst would generate larger pores, a higher acidity, and active interfaces at the calcining temperature of 300 °C. Therefore, HSiW@Ni-Zr-O-1 exhibits an excellent catalytic activity of 95.2% under optimal reaction conditions. Additionally, the catalyst can be reused with a good catalytic activity after nine cycles. This study highlights the opportunity of using bimetallic MOFs as precursors to the synthesis of highly nanoporous metal oxide, which supports the larger-industrial scale production of biofuels.