Atomically dispersed Rh on manganese oxide nanorod for catalytic C-H ammoxidation

Selective ammoxidation of sp 3 -hybridized C-H bonds is very important in the pharmaceutical and fine-chemical industries. However, simultaneous activation of the C-H bond and ammonia is difficult due to the competitive adsorption of ammonia and hydrocarbons on metal sites, which poisons the catalyst. In this study, we report an atomically dispersed rhodium (Rh) catalyst supported on manganese oxide nanorod that exhibited high activity and selectivity for the C-H bond ammoxidation under mild reaction conditions, outperforming the conventional supported metal catalysts and homogeneous manganese catalysts under the equivalent conditions. Mechanistic studies reveal that the manganese oxide nanorod with potassium ions in the tunnels significantly hindered the ammonia poisoning to Rh, providing free Rh sites for C-H bond activation and enhancing the ammonia-resistance of the catalyst. This work provides an opportunity to improve the efficiency of industrially important reactions that suffer from catalyst deactivation due to surface poisoning.