RSM-optimized dual-catalyst system: green and efficient synthesis of bio-based PETO from renewable plant-derived feedstocks

BACKGROUND Bio-based oleic acid pentaerythritol ester (PETO) is a crucial green feedstock for high-end high-temperature lubricants. Existing synthesis processes are hindered by low catalytic efficiency, high energy consumption, and suboptimal yields. OBJECTIVE This study aims to develop an efficient, low-energy green synthesis process for PETO. METHOD A ‘dibutyltin oxide (DBTO) + tetrabutylammonium bromide (TBAB)’ dual-catalyst system was used, and the transesterification process was optimized by ‘single-factor prescreening—Box-Behnken response surface optimization’. RESULTS The optimization model showed high reliability (R 2 > 0.99). Under optimized conditions (DBTO 1.56%, TBAB 0.7%, 269.86 °C, molar ratio 4.71:1, 4 h), PETO yield reached 96.89%, far exceeding conventional processes. TBAB synergistically enhances DBTO's catalytic efficiency by reducing interfacial resistance, and no water-carrying agent is needed. SIGNIFICANCE The integrated DBTO+TBAB dual-catalyst and RSM system provides a green, scalable PETO synthesis solution, facilitating industrial application and conforming to sustainable manufacturing principles. © 2026 Society of Chemical Industry (SCI).