Abstract Biodiesel production from the esterification of stearic acid with ethanol catalyzed by the mesoporous ZrO2/SiO2 catalysts which successfully synthesized by surfactant-assisted sol-gel auto-combustion method. These catalysts were characterized by various physico-chemical techniques such as XRD, BET surface area measurement, HR-TEM and NH3-TPD. The mesoporous catalyst prepared with cationic surfactant (ZrSiOC) showed a maximum BET surface area and pore volume. Interestingly, the ZrSiOC catalyst exhibited the largest acidity value among all catalysts. The results showed that the mesoporous ZrO2/SiO2 catalysts prepared with cationic (ZrSiOC) and non-ionic (ZrSiOT) surfactants demonstrated higher stearic acid conversion than those with anionic (ZrSiOS) or without surfactant (ZrSiO). Significantly, the ZrSiOC and ZrSiOT catalysts exhibited the highest conversion of 69.2% and 63.1% at 120 °C after 3 h, respectively. Additionally, it was observed that the conversion increased extremely with increasing the reaction temperature giving a maximum conversion of 76.9% at 125 °C by using the most active catalyst (ZrSiOC). Interestingly, the ZrSiOC catalyst displays suitable recycling as it kept performance of 72.5% after five recycle runs without significant lack in performance. Moreover, the kinetic study confirmed that esterification follows pseudo first-order equation.

中文翻译：

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表面活性剂辅助溶胶-凝胶自燃路线合成介孔ZrO2/SiO2催化剂硬脂酸酯化生产生物柴油

摘要 采用表面活性剂辅助溶胶-凝胶自燃法成功合成的介孔ZrO2/SiO2催化剂催化硬脂酸与乙醇酯化生产生物柴油。这些催化剂通过各种物理化学技术进行表征，例如 XRD、BET 表面积测量、HR-TEM 和 NH3-TPD。用阳离子表面活性剂 (ZrSiOC) 制备的介孔催化剂表现出最大的 BET 表面积和孔体积。有趣的是，ZrSiOC 催化剂在所有催化剂中表现出最大的酸度值。结果表明，用阳离子 (ZrSiOC) 和非离子 (ZrSiOT) 表面活性剂制备的介孔 ZrO2/SiO2 催化剂表现出比阴离子 (ZrSiOT) 或不含表面活性剂 (ZrSiO) 的那些更高的硬脂酸转化率。显着地，ZrSiOC 和 ZrSiOT 催化剂在 120°C 下 3 小时后的转化率分别为 69.2% 和 63.1%。此外，观察到转化率随着反应温度的升高而显着增加，通过使用活性最高的催化剂 (ZrSiOC)，在 125 °C 时的最大转化率为 76.9%。有趣的是，ZrSiOC 催化剂显示出合适的回收率，因为它在五次循环运行后保持 72.5% 的性能而没有明显的性能下降。此外，动力学研究证实酯化遵循伪一级方程。有趣的是，ZrSiOC 催化剂显示出合适的回收率，因为它在五次循环运行后保持 72.5% 的性能而没有明显的性能下降。此外，动力学研究证实酯化遵循伪一级方程。有趣的是，ZrSiOC 催化剂显示出合适的回收率，因为它在五次循环运行后保持 72.5% 的性能而没有明显的性能下降。此外，动力学研究证实酯化遵循伪一级方程。