Nitrogen-doped carbon black supported NiCoS catalyst for hydrogenation of nitrophenols under mild conditions.

Catalytic hydrogenation of nitrophenols to aminophenols was considered as the most efficient way to solve their contamination together with huge economic benefit. NiCoS can be used not only as supercapacitor materials, but also competitive catalytic materials in hydrogenation reactions. In this work, a nitrogen-doped carbon black (NCB) supported NiCoS catalyst is successfully prepared by a facile one-pot solvothermal approach. TEM results show that the ultrafine NiCoS particles are uniformly dispersed on the surface of NCB at a low NiCoS loading, while aggregation may occur in NiCoS/NCB catalysts with an excessive NiCoS content. The NiCoS-30/NCB catalyst with a BET surface area of 47.20 m g exhibits the most excellent catalytic activity and durability for heterogeneous catalytic hydrogenation of nitrophenols using NaBH as the reducing agent at 30 °C in the aqueous solution. The kinetic constant of hydrogenation of p-nitrophenol catalyzed by NiCoS-30/NCB is almost five times higher than the reaction catalyzed by pristine NiCoS. The outstanding performance of NiCoS-30/NCB is ascribed to the unique nanostructure of the catalyst and the combined effect between the NiCoS and NCB, including abundant surface functional groups of NCB for anchoring and dispersing NiCoS, strong adsorption ability for nitrophenol molecules facilitated by π-π stacking interaction, as well as fast electron transfer from NCB to NiCoS, resulting in higher local electron densities and thus facilitating the uptake of electrons by nitrophenols. [ABSTRACT FROM AUTHOR]