Fe3C nanoclusters integrated with Fe single-atom planted in nitrogen doped carbon derived from truncated hexahedron zeolitic imidazolate framework for the efficient transfer hydrogenation of halogenated nitrobenzenes

The control of morphology, structure and composition of metal–organic frameworks derived metal-nitrogen doped porous carbon (M–N–C) with high precision and accuracy is essential for the catalytic performance. While single-atom or small-sized nanometer catalysts show notable effects in catalysis, one catalyst combining the advantages of single-atom and nanometer catalysts may cultivate more benefits. Herein, we designed and successfully fabricated a series of Fe-doped ZIF–x with different morphologies (cube→truncated hexahedron→truncated octahedron) in one pot by simply adjusting the adding amount of vitamin C. After high-temperature calcination, Fe3C integrated with Fe single-atom planted in N-doped carbon (FeSA/FeNC–N–C–x) with various morphology, structure and composition could be acquired. Among them, FeSA/FeNC–N–C–0.75 exhibited the best catalytic performance for the transfer hydrogenation of halogenated nitrobenzenes with N2H4·H2O under room temperature. Acid-leaching tests, poisoning experiments, and the density functional theory calculations showed that Fe3C integrated with Fe single-atom had a better catalytic effect than the separated Fe3C or Fe single-atom.