抄録
Photocatalytic hydrogenation of nitroaromatics was carried out with silica-supported iron oxides (FeOx/SiO2) as catalysts and hydrazine monohydrate as a reductant. Photoirradiation of the catalysts at λ>300 nm promotes hydrogenation of nitroaromatics to the corresponding anilines with more than 90% selectivity. The FeOx/SiO2 catalysts with lower Fe loadings possess monomeric FeIII species behaving as the active sites and exhibit higher photocatalytic activity and aniline selectivity. Electron spin resonance (ESR) analysis revealed that photoexcitation of the hydrazine-adsorbed monomeric FeIII species produces FeII species by the reduction with hydrazine. The FeII species promote the reduction of nitroaromatics to anilines, along with the FeII→FeIII oxidation.
