Cobalt Silicides Nanoparticles Embedded in N-Doped Carbon as Highly Efficient Catalyst in Selective Hydrogenation of Cinnamaldehyde

摘要

Metal silicides are unconventional heterogeneous catalysts. Herein, cobalt silicide nanoparticles (NPs) embedded in Ndoped carbon (CoxSi@CN) catalysts have been synthesized by microwave-assisted silicification of metal-organic frameworktemplated Co@CN NPs successfully. The phase transitions of cobalt silicide can be controlled by the numbers of microwave cycles. The synthesized CoxSi@CN-2 catalyst possesses an ordered and uniform porous structure, high cobalt content (8.85 at.%), high specific surface area (236 m2 g1), and highly dispersed and small NPs (10-15 nm). The cobalt silicide catalyst is firstly used for selective hydrogenation of cinnamaldehyde. Owing to the strong modification of geometric structure and electronic properties by silicon, the particle size effect, and the Mott-Schottky effect at the metal-support interface, the assynthesized CoxSi@CN exhibits catalytic performance that is superior to its counterpart Co@CN. In addition, this silicide catalyst sustains the robust stability in hydrogenation of cinnamaldehyde.