Effect of Synthetic Routes on the Catalytic Activity of FePO4 for p-Nitrophenol Reduction

The catalytic application of FePO4 synthesized by various chemical routes for the conversion of p‑nitrophenol to p-aminophenol was investigated. The catalyst preparation involved solution technique, polymeric precursor, combustion and reverse micelle methods. The influence of synthetic methods on the catalytic behavior was studied. Characterization of FePO4 was carried out by powder XRD, FT-IR and SEM analysis. The conversion of p-nitrophenol was monitored by UV–Vis spectrophotometer and p-aminophenol was confirmed by UV–Vis, FT-IR, HPLC, 1H NMR and mass spectrometric techniques. FePO4 prepared by combustion method using citric acid showed highest activity due to the large surface area. The conversion of p-nitrophenol to p-aminophenol was achieved in 50 s. The p-nitrophenol reduction reaction follows pseudo-first-order kinetics. The apparent rate constant was found to be 5 × 10–3 s–1 for 0.2 mmol L–1. The results show that FePO4 can be used as an effective catalyst for the hydrogen generation.