Fe-based N-doped dendritic catalysts for catalytic ammoxidation of aromatic aldehydes to aromatic nitriles.

Non-noble-metal-based catalysts for catalyzing the oxidative coupling of aldehydes and ammonia represent an efficient atom-economical synthetic route to produce nitriles. In this study, an effective Fe-modified N-doped carbon catalyst anchored on fibrous silica nanospheres (Fe-N/KCC-1-T) was successfully prepared by a facile strategy. 1,10-Phenanthroline with a strong chelating ability ensured the homogeneous, ultrafine distribution of Fe-based active sites, and the KCC-1 support material effectively enhanced the accessibility to these active sites, which corresponded to center-radial pore channels and a high surface area. As-fabricated Fe-N/KCC-1-T exhibited excellent catalytic performance for the ammoxidation of aldehydes under mild reaction conditions. A series of functionalized aldehydes were efficiently oxidized into the corresponding nitriles by using air as the green oxidant. Moreover, the catalyst was recycled for at least five runs without any clear decrease in the performance. Hence, this study is expected to provide an eco-friendly synthetic route to produce nitriles from easily available aldehydes and ammonia by using a cost-effective catalyst.