Highly dispersed palladium nanoparticles supported on graphitic carbon nitride for selective hydrogenation of nitro compounds and Ullmann coupling reaction

High catalytic activity and superior stability are important criterion for the utilization of a noble metal-based nano-composite catalyst. Herein, we report a facile synthesis of highly dispersed palladium nanoparticles embedded on graphitic carbon nitride (Pd@CNx) by ultrasound assisted method without aid of any external reducing agent. The Pd@CNx composite was well characterized by different techniques. This Pd@CNx shows effective catalytic activity towards easy dehydrogenation of sodium borohydride (NaBH4) and ammonia borane in aqueous medium and also can easily hydrogenate 4-nitrophenol to 4-aminophenol with fast kinetics. The catalyst is highly selective towards nitro groups in presence of other reducible groups with good stability. Furthermore, the catalyst exhibits superior catalytic activity towards Ullmann coupling reaction of different aryl halides with broad range of substrates scope with easy recovery of the catalyst and notable recycling property.

Automated summary

The synthesized Pd@CNx composite exhibits high catalytic activity and selectivity, effective in catalyzing the dehydrogenation of NaBH4 and ammonia borane in aqueous medium, as well as hydrogenation of 4-nitrophenol to 4-aminophenol. The catalyst shows high selectivity towards nitro groups and superior catalytic activity in Ullmann coupling reaction.