Heteropolyacid (H3PW12O40)-impregnated mesoporous KIT-6 catalyst for green synthesis of bio-diesel using transesterification of non-edible neem oil

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, N-2-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 degrees C. Further, the spent catalyst was recovered and recycled three times, and it showed activity losses of less than 4%.