Niobia as an efficient catalyst for the epoxidation of dicyclopentadiene

We studied the epoxidation of dicyclopentadiene (DCPD) with hydrogen peroxide over different heterogeneous catalysts. Among them, niobium pentoxide (Nb₂O₅) catalysts showed promising catalytic activity, giving mono- and di-epoxy DCPD with low amounts of epoxidation byproducts. The epoxidation activity of Nb₂O₅ largely depends on the reaction solvents. Higher epoxidation performance was observed in the solvents with a certain range of dielectric constants (30 < ε_r < 40), such as methanol and acetonitrile. The crystallinity of the Nb₂O₅ catalysts was modified by calcination temperature, which influences the formation of surface peroxo species, and consequently, the extent of the DCPD epoxidation.