catalyzed schiff base synthesis over bifunctinalized cobalt/zinc-incorporated mesoporous silica nanoparticles under uv irradiation

A novel series of the cobalt/zinc-mesoporus silica nanoparticles (denoted by cz-msn) catalysts with si/zn molar ratio of 10 and 1, 3, 5 and 7 wt% cobalt were synthesized using post-synthesis methods. the samples were characterized by xrd, sem, ftir, tem and nitrogen adsorptiondesorption methods. an increasing amount of cobalt species from 1 to 7 wt% at constant ratio of si/zn, leading the reduction of catalyst surface from 408 m2g-1 to 322 m2g-1. the catalytic activities for the synthesis of the schiff base was investigated through the reaction of cyclohexanone with 2,4-dinitrophenylhydrazine under uv irradiation. the activity of the catalysts in the formation of the schiff base followed the cobalt amounts of 0<1<7<3<5. the sample with cobalt 5 wt% exhibited the highest performance with the conversion and selectivity of 98 and 97% respectively, under uv light at 298 k for 10 min. the superior catalytic performance of the catalyst with cobalt 5 wt% includes high yield, low reaction temperature, short reaction time and eco-friendly. we assume that the reason would be related to the stronger metal-support interaction and metals dispersion. this study provides the new perspective on the synthesis of cz-msn towards an excellent performance of schiff base structure under uv irradiation.