Synthesis of Pd on porous hollow carbon spheres as an electrocatalyst for alcohol electrooxidation

Porous hollow carbon spheres (PHCSs) are prepared with glucose as the carbon source and a solid core microporous shell silica (SCMSS) as the template. The PHCSs are composed of broken and complete hollow carbon spheres cemented to each other. There are big gaps between the PHCSs which make it possible to utilize the inner wall of the hollow carbon spheres as an electrocatalyst support. The PHCSs have a high Brauner-Emett-Teller (BET) surface area of 998.1 m(2) g(-1), and a pore volume of 1.88 cm(3) g(-1). The Pd nanoparticles supported on PHCS electrocatalysts are highly active for methanol, ethanol and isopropanol electrooxidation. Pd/PHCS has a 3.1 times higher in peak current density and a 80 mV negatively shifted onset potential compared with that of a Pd/C electrocatalyst at the same Pd loadings for ethanol electrooxidation. The porous structure of Pd/PHCS is favorable for mass transfer and remains high activity in higher concentration of ethanol. The Pd/PHCS electrocatalyst is a potential candidate for application in direct liquid alcohol fuel cells.