Fe/Fe₃C Encapsulated in N‑Doped Carbon Tubes: A Recyclable Catalyst for Hydrogenation with High Selectivity

Herein, a series of Fe-based catalysts have been designed and prepared by grinding a mixture of MIL-88d and melamine, and then the mixture was followed by pyrolysis. An unusual Fe/Fe₃C-activated site is uniformly encapsulated in the N-doped carbon tubes obtained by pyrolysis of the film-like nanocrystals of MIL-88d. Experimental characterizations and theoretical calculations demonstrate that the surface N sites can effectively trap the nitrobenzene and aniline by their phenyl groups with the formation of three C–N bonds that made the catalyst exhibit excellent catalytic activity (turnover frequencies of ≤11268 h^–1 calculated on the basis of nitrobenzene) and chemoselectivity for the reduction of nitro derivatives under facile conditions.