Facile synthesis of highly stable heterogeneous catalysts by entrapping metal nanoparticles within mesoporous carbon

Cycling instability is a persisting problem in heterogeneous catalysis. Here we report an efficient strategy to enhance the recyclability of the heterogeneous catalysts by in situ entrapment of active nanoparticles in mesoporous carbon. A hard template method was used to fabricate the desired catalyst, where Al₂O₃ was employed as the template and polyphenols were used as carbon source as well as the stabilizing agent. Based on N₂ adsorption/desorption analysis, the catalysts adopt the high surface area of the Al₂O₃ template and feature mesoporous pores. Additionally, the noble metal nanoparticles (Pd) were found to be well entrapped inside the carbon matrix with good dispersion. The as-prepared catalysts were highly active in various heterogeneous hydrogenations of C=C containing substrates (quinoline, cinnamaldehyde, etc.) and exhibited excellent cycling stability without any significant loss of activity for 10 recycles, which is superior to that of the commercial Pd/C catalyst.