Natural α-Fe2O3 as an efficient catalyst for the p-nitrophenol reduction

Abstract 4 nitrophenol (4-NP) is a recalcitrant water pollutant. It reduces to 4 aminophenol (4-AP), which is a less harmful compound. Typically, a noble metal catalyzes this reaction. However, its preparation is complex and expensive. Here, for the first time, we test hematite either from natural goethite calcination and compared with a synthetic hematite prepared by citrate or traditional precipitation method. We characterize the catalysts by thermo gravimetric analysis (TGA), X-ray fluorescence (XRF), X-ray diffraction (XRD) transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), particle size distribution (PSD), and nitrogen adsorption desorption at 77 K. 4-NP reacted in presence of NaBH 4 as the reducing agent to 4-AP. Kinetic study and catalyst stability were performed. Particle morphology played an important role in the reaction. All samples exhibited high catalytic activity with first order kinetic constants of 0.024, 0.027, 0.037 s −1 for natural α-Fe 2 O 3 , hematite prepared by precipitation, and citrate method, respectively.