Iron-nickel alloy particles with N-doped carbon “armor” as a highly selective and long-lasting catalyst for the synthesis of N-benzylaniline molecules

A scalable strategy for the convenient and rapid preparation of nitrogen-doped carbon-coated iron-based alloy catalysts was developed. By controlling the type and amount of metal salts in the precursor, various types of nitrogen-doped carbon-coated alloy catalysts can be prepared in a targeted manner. Fe₂Ni₂@CN materials with small particle sizes and relatively homogeneous basic sites showed promising results in the N-alkylation reaction of benzyl alcohol with aniline (optimum yield: 99%). It is worth noting that the catalyst can also be magnetically separated and recovered after the reaction, and its performance can be regenerated through simple calcination. Furthermore, it was confirmed by kinetic experiments that the activation of C–H at the benzyl alcohol benzylic position is the rate-determining step (RDS). According to density flooding theory calculations, Fe₂Ni₂@CN catalysts require less energy than other materials (Fe@CN and Ni@CN) for the RDS (dehydrogenation reaction) process. Therefore N-alkylation reactions are more easily carried out on Fe₂Ni₂@CN catalysts, which may be the reason for the best catalytic activity of Fe-Ni alloy materials. These carbon-coated alloy materials will show great potential in more types of heterogeneous catalysis.