Constructing membrane electrodes of low Pt areal loading with the new support of N-doped carbon nanocages for PEMFC

Abstract

Proton exchange membrane fuel cell (PEMFC) has great commercialization prospects. For lowering the cost of PEMFC, constructing membrane electrode assembly (MEA) with high power density and low Pt areal loading is critical. Herein, the Pt catalysts with high Pt weight fractions of 40–80 wt% were synthesized by using hierarchical carbon nanocages (hCNC) and N-doped hCNC (hNCNC) as the supports. The Pt nanoparticles on hNCNC (Pt/hNCNC) exhibited superior oxygen reduction reaction (ORR) performance to those on hCNC in half cells. The membrane electrode with low Pt areal loading (0.17 mgPt·cm−2 at cathode) was constructed with Pt/hNCNC (60 wt%), which exhibited the maximum power density of 1.040 W cm−2 and the mass activity of 6.49 A·mgPt-1 at 0.6 V, close to commercial Pt/C (60 wt%). Such an excellent performance results from the uniform dispersion and tuned electron density of Pt nanoparticles due to the N-doping, and the efficient mass/charge synergistic transfer due to the combination of hierarchical architecture with good conductivity of the hNCNC support. This study demonstrates the significant potential of hNCNCs as new support to construct advanced fuel cell catalysts.