Nitrogen doped carbon supported iron catalysts for highly selective production of 4,4′-diamino-2,2′-stilbenedisulfonic acid

Nitrogen doped carbon supported iron catalysts were prepared from pyrolysis of a multidentate nitrogen ligand iron complex supported on chitosan at different temperature, and showed good performances in the reduction of 4,4′-dinitrostilbene-2,2′-disulfonic acid (DNS acid) to 4,4′-diamino-2,2′-stilbenedisulfonic acid (DSD acid) with hydrazine hydrate (N2H4·H2O) as reductant. Characterization results revealed that the iron is mainly present in the form of Fe2O3 and metallic iron nanoparticles. The doped N atoms functionalized as anchoring sites to stabilize iron nanoparticles, which endows the catalysts with excellent activity and superior reusability.