Hollow macroporous core/mesoporous shell carbon with a tailored structure as a cathode electrocatalyst support for proton exchange membrane fuel cells

Well-tailored spherical carbon capsules with a hollow macroporous core of ca. 280 nm and a ca. 40 nm thick mesoporous shell were synthesized and explored for the first time as cathode catalyst support in proton exchange membrane fuel cells (PEMFC). The unique structural characteristics of hollow core/mesoporous shell (HCMS) carbon including high specific surface area, large pore volume, uniform particle size, and well-developed three-dimensionally interconnected bimodal porosity make it an ideal candidate as catalyst support for lowtemperature fuel cells. Considerable improvements in electrocatalytic activity toward oxygen reduction reactions and in fuel cell performance have been achieved by Pt(20 wt %) supported on the HCMS carbon (HCMSC) when compared with its counterpart, Pt supported on commonly used commercially available catalyst support carbon black Vulcan XC-72 (VC), suggesting that the HCMSC is an excellent and much more efficient cathode catalyst support than VC for PEMFC application.