Highly dispersed Co species in N-doped carbon enhanced the aldehydes ammoxidation reaction activity

Developing environmentally friendly catalysts with high activity for the ammoxidation of aromatic aldehydes to aromatic nitriles is greatly important for this industrial transformation. Herein, natural vitamin B12 was used as a carbon source for the preparation of a cobalt- and nitrogen-doped catalyst precursor, which was pyrolyzed at different temperatures to obtain cobalt- and nitrogen-doped carbon (Co@NC-T) (T denotes pyrolysis temperature) catalysts. The Co@NC-800 exhibited excellent activity and selectivity in the ammoxidation of aromatic aldehydes with ammonium carbonate to aromatic nitriles compared to the Co@NC-700, Co@NC-600 and Co@NC-500 catalysts. The high catalytic performance of Co@NC-800 could be due to the presence of the lowdensity electron cloud of the highly dispersed Co species, which could interact with the benzene ring of benzaldehyde bearing p-pi conjugate, thereby promoting the adsorption and activation of benzaldehyde. Consequently, the activated benzaldehyde reacted with amino groups that were decomposed from ammonium carbonate and subsequently underwent a dehydration process to form nitriles.

Automated summary

Developing environmentally friendly catalysts with high activity for the ammoxidation of aromatic aldehydes to aromatic nitriles is crucial for industrial transformation. In this study, cobalt- and nitrogen-doped carbon catalysts were prepared using natural vitamin B12 as a carbon source, and Co@NC-800 exhibited superior catalytic performance due to the interaction between highly dispersed cobalt species and benzaldehyde. The activated benzaldehyde reacted with amino groups from ammonium carbonate and underwent a dehydration process to form nitriles.