The role of the KCaF3 crystalline phase on the activity of KF/CaO biodiesel synthesis catalyst.

Abstract KF-loaded CaO is known as a good solid base catalyst for biodiesel synthesis. KCaF 3 is generated when the KF/CaO catalyst is prepared, but its role in biodiesel synthesis is uncertain. Herein, we systematically investigated how KCaF 3 affected the transesterification reaction to yield biodiesel. We found that KCaF 3 , by itself or as a component in KF/CaO, had no catalytic activity in biodiesel synthesis. Its real role was to improve the mechanical strength and structural robustness of the catalyst, thereby enhancing the catalytic activity of KF/CaO in transesterification reaction. Graphical abstract Unlabelled Image Highlights • The component of KCaF 3 in KF/CaO catalyst was found to have no basicity. • KCaF 3 was also demonstrated to be inactive in the transesterification reaction. • The key role of KCaF 3 is to improve the mechanical strength and structural robustness of KF/CaO. • KCaF 3 endows the catalyst with enhanced activity in transesterification reaction. [ABSTRACT FROM AUTHOR]