Study on Epoxidation of Cyclopentene Catalyzed by Diniobium Pentoxide Loaded on Carbon@Silica Composite Material

Using polybenzoxazine as carbon and nitrogen sources and tetraethyl silicate as silicon source, a hollow carbon nitride@silica composite material was synthesized by limited carbonization method.Using niobium pentachloride as niobium source, Nb2O5 was loaded on hollow carbon nitride@silica composite by impregnation-calcination method.The epoxidation of cyclopentene was catalyzed by the amphiphilic catalyst Nb2O5/CNx@mSiO2 with H2O2 (aqueous solution) as oxidant.The catalytic active center Nb2O5 is mainly anchored to the hollow and hydrophobic carbon nitride skeleton through nitrogen atoms, and the inner cavity structure can enrich more cyclopentene.The outer hydrophilic mesoporous silica can not only protect the catalytic active center to reduce its loss, but also facilitate the separation and recovery of the catalyst.Under the optimal reaction conditions, the conversion of cyclopentene was 94.0% and the selectivity of cyclopentane oxide was 92.1%.The catalyst can be recycled three times.This study provides a new green and efficient method for the preparation of cyclopentane oxide and a new idea for the aqueous oxidation of olefin catalyzed by amphiphilic catalyst.Keywords amphiphilicity; carbon@silica; niobium oxide; epoxidation; cyclopentane oxide 环氧环戊烷(CPO)是一种重要的有机合成中间体和 原料, 广泛用于增塑剂、医药、香料、农药等生产 [1] .石 化工业中 C5 馏分的主要副产品为环戊二烯, 环戊二烯 的选择性加氢可以很容易地获得丰富的环戊烯(CPE) [2] .H 2 O 2 作为氧化剂, 副产物为水, 环境友好