Benzoselenadiazole-based nanoporous Covalent Organic Polymer (COP) as efficient room temperature heterogeneous catalyst for biodiesel production

Biodiesel production through esterification of fatty acids by solid heterogeneous catalysts has gained huge importance due to their usefulness as alternative fuel source. Here, we report the synthesis of benzoselenadiazolebased nanoporous covalent organic framework COP-1 via Sonogashira coupling reaction and COP-2 functionalized with SO3H group through HSO3-Cl treatment with COP-1. The solid heterogeneous catalyst COP-2 endows the synthesis of biodiesel via esterification of free fatty acids at room temperature at a faster rate. Solid-state C-13 NMR and FT-IR spectroscopic data confirm the synthesis of COP-1 and COP-2. COP-1 and COP-2 show nanoporous structure with surface area of 471.8 and 158.66 m(2) g(-1) and pore size of 11.42 nm and 4.49 nm. The sulfonated nanoporous COP-2 shows excellent catalytic property in the esterification of fatty acids with TON 83.33 and 100% yield.