Catalytic activity of first row transition metal oxides in the conversion of p-nitrophenol to p-aminophenol

The catalytic activities of first row transition metal oxides in the conversion of p-nitrophenol to p-aminophenol were investigated. The conversion was carried out at room temperature (30° C) using aqueous sodium borohydride. The reduction process was accelerated by CuO, Co3O4, Fe2O3 and NiO. The oxides such as TiO2, V2O5, Cr2O3, MnO2 and ZnO were found to be inactive towards the conversion of the nitrophenol. The active catalysts were analyzed before and after the reaction by XRD and the reduction reaction was monitored and confirmed by UV–vis, HPLC, 1H NMR and FT-IR techniques.

The borohydride reduction of p-nitrophenol to p-aminophenol was carried out at room temperature in the presence of first row transition metal oxides. The catalytic activity was significantly affected by the nature of the transition metal oxides. The reduction process was accelerated by the oxides CuO, Co3O4, Fe2O3 and NiO.Figure optionsDownload high-quality image (96 K)Download as PowerPoint slideHighlights
► Metal oxides possessing ‘dn’ (n = 5–9) electronic configuration are active.
► The oxides with ‘d0’, ‘d3’ and ‘d10’ configurations are inactive.
► Active oxides are CuO, Co3O4, Fe2O3 and NiO.
► Copper and cobalt oxides are evolved as better catalysts with low concentration of NaBH4.