Optimization of\nBiolubricant Synthesis Using Heterogeneous\nCatalysis: A Response Surface Methodology Approach

In this study, KIT-6, a cubic mesoporous silica with\nan Ia3d structure,\nwas modified with varying amounts of zirconium and sulfate groups\nand used as a catalyst for biolubricant synthesis through the esterification\nof oleic acid and trimethylpropane (TMP). Characterization by Fourier\ntransform infrared spectroscopy, scanning electron microscopy, energy-dispersive\nX-ray spectroscopy, and X-ray diffraction (confirmed the successful\nincorporation of zirconium and sulfate groups without altering the\nprimary mesoporous structure. The reaction conditions were optimized\nusing response surface methodology with variables including temperature,\noleic acid/TMP ratio, catalyst concentration, and catalyst type. The\noptimized conditions (160 °C, 2.0% catalyst, 3:1 oleic acid/TMP\nratio, and KIT-6(10) as the catalyst) resulted in an 86.0% conversion\nyield, confirmed by nuclear magnetic resonance <sup>1</sup>H NMR analysis.\nPostreaction analyses demonstrated the structural stability of the\ncatalyst under reaction conditions, indicating its suitability for\nmultiple applications. This work highlights the potential of modified\nKIT-6 in catalysis, offering insights into reaction efficiency and\ncatalyst stability.