Wormholelike mesoporous carbon supported Pt Ru catalysts toward methanol electrooxidation

Wormholelike mesoporous carbons(WMCs) with three different pore diameters(D_p),namely WMC-F7(D_p=8.5nm),WMC-F30(D_p=4.4nm),and WMC-FO(D_p = 3.1nm) are prepared via a modified sol-gel process.Then PtRu nanoparticles with the particle size(d_(Pt)) of ~3.2 nm supported on WMCs are synthesized with a modified pulse microwave-assisted polyol method.It is found that the pore diameter of WMCs plays an important role in the electrochemical activity of PtRu toward alcohol electrooxidation reaction.PtRu/WMC-F7 with Dp 2d_(Pt) exhibits the largest electrochemical surface area(ESA) and the highest activity toward methanol electrooxidation.With the decrease in D_p,PtRu/WMC-F30 and PtRu/WMC-FO have much lower ESA and electrochemical activity,especially for the isopropanol electrooxidation with a larger molecular size.When D_p is more than twice d_(Pt),the mass transfer of reactants and electrolyte are easier,and thus more PtRu nanoparticles can be utilized and the catalysts activity can be enhanced.