Hydrodechlorination of 4-Chloro-2-Aminophenol into a Recyclable Product Using Ni- and Cu-Based Catalysts

The 4-chloro-2-amino phenol (4C2AP) bearing wastewater is produced while manufacturing dyes and pharmaceutical ingredients. Ni- and Cu-based cost-effective catalysts were developed, typically characterized, and subjected to hydrodechlorination (HDC) of 4C2AP. The role of reducing agents, concentration, pH of wastewater, presence of salt, reaction temperature, catalyst reuse, and the kinetics was investigated. A selective makeover of 2-amino phenol (2AP) was analyzed by HPLC, LCMS, and NMR. A complete HDC of 4C2AP with remarkable selectivity (98%) toward 2AP was achieved using a Ni0 catalyst and NaBH4 at room temperature. It is observed that the alkaline condition, the presence of salt, and a high reaction temperature favor the HDC process. A maximum of 1 g L–1 of the Ni0 loading is found to be sufficient to dechlorinate the pollutant. It can be concluded that the catalytic HDC is a technically viable and inexpensive process for the conversion of 4C2AP into a valuable product, 2AP.