Wormholelike mesoporous carbon supported PtRu catalysts toward methanol electrooxidation

Abstract Wormholelike mesoporous carbons (WMCs) with three different pore diameters ( D p ), namely WMC-F7 ( D p  = 8.5 nm), WMC-F30 ( D p  = 4.4 nm), and WMC-F0 ( D p  = 3.1 nm) 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 D p  > 2 d 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-F0 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.