Filled cobalt nanoparticles into carbon nanotubes as a rapid and high-efficiency catalyst for selective epoxidation of styrene with molecular oxygen

• Cobalt nanoparticles uniformly dispersed in carbon nanotubes with wet chemistry method.
• Our reaction time is the shortest and yield is the highest at appropriate temperature.
• The catalysts were recycled three times without significant loss activity.

A new nanocatalyst has been synthesized by a simple and effective wet chemical method confined magnetic cobalt nanoparticles within carbon nanotubes (CNTs). We characterized the catalysts by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and vibrating sample magnetometer (VSM). The TEM results demonstrated that the cobalt nanoparticles were filled into the CNTs successfully. In the meantime, the CNTs mesostructure were not destroyed in multistep synthetic procedure. In the catalytic activity test, liquid phase epoxidation of styrene by molecular oxygen was carried out at atmospheric pressure employed Co/CNTs (in) catalysts. The results showed that styrene conversion over 99% and epoxide selectivity of 93% for 1 h reaction. The catalysts can be easily separated from the reaction mixtures by external magnet, and reused three times without significant loss in catalytic activity.