ZnNb2O6 fibre surface as an efficiently product-selective controller for the near-UV-light-induced nitrobenzene reduction reaction†
A high aniline yield was achieved by the combination of near-UV light as the driving force of nitrobenzene reduction and a ZnNb2O6 surface as the product-selective controller. Here, a ZnNb2O6 fibre, having a wide band gap and both acidic and basic sites, was exploited by a novel ion-exchange method to study the effect of the surface acidity and basicity of catalysts on the product selectivity under near-UV light irradiation without the interference of photo-generated carriers. ZnNb2O6 showed the highest aniline yield compared to Nb2O5 and ZnO. The results of experimental and theoretical calculations confirmed that the acidic sites on the surface of ZnNb2O6 promoted the breakage of the N–O bond in the intermediate phenylhydroxylamine while the basic sites were attached to the dissociated hydrogen of isopropyl alcohol, resulting in high aniline selectivity.