Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 106335, Taiwan.
Center for Nanoscience and Technology, Anna University, Chennai 600025, Tamil Nadu, India.
J Nanosci Nanotechnol. 2021 Jun 1;21(6):3237-3248. doi: 10.1166/jnn.2021.19323.
The present work focus on the synthesis of x% SO₄ loaded SnO₂ nanocatalyst at different percentages ( = 2.3, 4.6, 6.9, 9.2, and 11.5% w/w) for acid-catalyzed esterification. The synthesized catalysts were characterized by X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), brunauer-emmett-teller (BET), scanning electron microscopy (SEM), transmission electron microscope (TEM), temperature-programmed desorption, and thermal gravimetric analysis (TGA/DTA) techniques. Methyl levulinate is an important chemical feedstock and its production through a catalytic route has been explored in this work. All the synthesized catalysts show excellent catalytic activity towards liquid-phase esterification of levulinic acid (LA) in atmospheric pressure under non-corrosive and mild conditions. The various reaction parameters like the effect of sulfate content, reaction temperature, reaction time, molar ratio of reactants, and prepared catalyst weights are optimized to get the highest conversion and selectivity of methyl levulinates. Among them, as prepared 6.9% SO₄ /SnO₂ catalyst exhibits the highest conversation of levulinic acid (98%) and more selectivity towards methyl levulinate (100%). The catalytic stability and recyclability of the most active nanocatalysts were performed up to five successive runs and proves less variation in the catalytic activity.
本工作重点研究了不同负载量（ = 2.3、4.6、6.9、9.2 和 11.5% w/w）的 x% SO₄ 负载的 SnO₂ 纳米催化剂在酸催化酯化反应中的合成。所合成的催化剂采用 X 射线粉末衍射（XRD）、傅里叶变换红外光谱（FT-IR）、BET、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、程序升温脱附（TPD）和热重分析（TGA/DTA）技术进行了表征。甲基戊酸酯是一种重要的化学原料，本工作探索了通过催化途径生产它的方法。所有合成的催化剂在非腐蚀性和温和条件下，在大气压力下对戊酸（LA）的液相酯化反应都表现出优异的催化活性。优化了各种反应参数，如硫酸盐含量、反应温度、反应时间、反应物摩尔比和制备催化剂的重量，以获得最高的甲基戊酸酯转化率和选择性。其中，制备的 6.9% SO₄ /SnO₂ 催化剂表现出最高的戊酸转化率（98%）和更高的甲基戊酸酯选择性（100%）。最活跃的纳米催化剂的催化稳定性和可回收性进行了多达五次连续运行的测试，证明其催化活性变化不大。
