Highly Selective Glycerol Esterification over Silicotungstic Acid Nanoparticles on Ionic Liquid Catalyst

The aim of this work was to study the production, characterization, and performance of ionic liquid (IL) on silicotungstic acid (STA-IL) via the sol–gel method as catalysts in the esterification of oleic acid (OA) and purified glycerol, as well as to examine the effects of IL on heterogeneous catalysts. The STA-IL catalyst showed a relatively high surface area of 88.36 m2/g due to the presence of nanoporous silica. XPS analyses showed the significant formation of W–O–Si, W–O–W, and Si–O–Si bonding. The STA-IL catalyst enabled a conversion of 96% of OA with a significantly higher monoolein selectivity and yields of 96% and 92.2%, indicating that it is the more efficient solid acid catalyst. The presence of IL serves as PTC or medium, enhancing reaction synergistic effect. In addition, the ease of separation of the STA-IL catalyst due to its insolubility in the product phase can improve the recyclability.