Porous carbon supported Pd catalysts derived from gelatin-based/chitosan or polyvinyl pyrrolidone/PdCl2 blends

Novel N-containing porous carbon supported Pd heterogeneous catalysts have been derived by carbonization of gelatin (GEL)/chitosan/PdCl2 (GEL/CS/PdCl2) and GEL/polyvinyl pyrrolidone/PdCl2 (GEL/PVP/PdCl2) blends under N-2 atmosphere at 800 degrees C. The microstructure of the resultant N-containing carbon supported Pd heterogeneous catalysts can be tailored by the nature of the blended polymers. Much larger specific surface area, better dispersion of Pd-0/PdO nanoparticles, higher Pd and N contents are found in the case of N-containing porous carbon supported Pd heterogeneous catalysts derived from GEL/CS/PdCl2 blend system. When the mass ratio of GEL to CS is kept at 1/1, the surface area of 644.8 m(2)/g, rich porous structure, N % of 7.2%, and Pd-0/PdO nanoparticles sized below 3 nm are obtained in the derived Pd@N-C-GEL/CS(1/1) catalyst. It shows excellent catalytic efficiency (higher than 90%) in Heck coupling reaction of aromatic halides and alkenes, and high recycling stabilities both in aqueous (9 runs) and organic (15 runs) phase. The high activity and stability of the novel Pd@N-C-GEL/CS(1/1) catalyst have been attributed to a combination of high porous structure, strong chelation of Pd species, high thermal stability, and good solvent-resistant performances.

Automated summary

Novel N-containing porous carbon supported Pd heterogeneous catalysts were prepared by carbonization of different blended polymers. The microstructure of the catalysts could be tailored by the nature of the blended polymers. The catalyst derived from GEL/CS/PdCl2 blend showed larger specific surface area, better dispersion of Pd-0/PdO nanoparticles, and higher Pd and N contents. It exhibited excellent catalytic performance in the Heck coupling reaction of aromatic halides and alkenes.