Mesoporous Ia3d cubic structured KIT-6 support was prepared by hydrothermal strategy and heteropoly acid content (10, 20 and 30%) was stacked on KIT-6 by wet-impregnation technique. The synthesized catalysts were characterized by XRD, N₂-sorption, NH₃-TPD, ATFT-IR, TEM and SEM–EDAX analyses. Acid properties of the supported catalysts were investigated by pyridine-adsorbed ATFT-IR and NH₃-TPD, respectively. Poly-anion coordination present in the catalyst was confirmed by the DRS-UV spectrum. The dispersion of heteropoly acid on the catalyst surface was observed by TEM analysis. Also, the presence of the elements such as W and P on the catalyst and its morphology were represented by the HRSEM–EDAX technique. The catalytic activity of HPWA/KIT-6 was investigated by the transesterification of neem oil with methanol. Among the different wt% catalyst, 20% catalyst showed highest neem oil conversion and selectivity at an optimized reaction temperature of 60 °C. Further, the spent catalyst was recovered and recycled three times, and it showed activity losses of less than 4%.

中文翻译：

---

杂多酸（H 3 PW 12 O 40）浸渍的中孔KIT-6催化剂，用于非食用印oil油的酯交换反应，绿色合成生物柴油

通过水热法制备介孔的Ia3d立方结构的KIT-6载体，并通过湿浸渍技术将杂多酸含量（10％，20％和30％）堆叠在KIT-6上。通过XRD，N ₂吸附，NH ₃ -TPD，ATFT-IR，TEM和SEM-EDAX分析对合成的催化剂进行了表征。通过吡啶吸附的ATFT-IR和NH ₃研究了负载型催化剂的酸性质-TPD。通过DRS-UV光谱证实了催化剂中存在的聚阴离子配位。通过TEM分析观察杂多酸在催化剂表面上的分散。另外，HRSEM-EDAX技术代表了催化剂中W和P等元素的存在及其形态。通过印em油与甲醇的酯交换反应研究了HPWA / KIT-6的催化活性。在不同wt％的催化剂中，在最佳反应温度60°C下，20％的催化剂显示出最高的印度em树油转化率和选择性。此外，将废催化剂回收和再循环三遍，其活性损失小于4％。