Facile growth of ultra-small Pd nanoparticles on zeolite-templated mesocellular graphene foam for enhanced alcohol electrooxidation

摘要

Labor-saving preparation of highly active electrocatalysts for alcohols oxidation, especially for the ethylene glycol and glycerol electrooxidation is of great importance for the development of fuel cells. Herein, mesocellular graphene foam (MGF) constructed by ultrathin nanosheets were prepared using lamellar MCM-22 zeolite as template and then ultra-small Pd NPs were facile grew on it via the stabilizer-free synthesis. Detailed characterizations showed that the obtained Pd/MGF had large surface area, hierarchical porous architecture, semi-graphitic framework and dispersed Pd NPs an chori ng. Electrochemical measurements dem on strated that Pd/MGF possessed the higher catalytic activity (1.7-2.9 fold higher) and stability for the different alcohols electrooxidation, especially for the ethylene glycol and glycerol electrooxidation in the alkaline solution, than the commercial Pd/C (10 wt.%) catalyst. Reaction kinetics analysis revealed the expanded diffusion-controlled process of Pd/MGF as compared to Pd/C. These findings promised a potential electrocatalyst for direct alcohol fuel cells (DAFC), especially for the direct ethylene glycol or glycerol fuel cells with high energy density.