Fig. 2: Performance evaluation of the Pt-Fe-N-C cathode in the fuel cell.
a, H2/O2 fuel cell polarization (solid symbols and left axis) and power density (hollow symbols and right axis) plots with loadings of 0.1 mgPt cm−2 for Pt/C (black triangles) and Pt–N–C (yellow diamonds), and 0.015 mgPt cm−2 for Pt-Fe-N-C (red circles), and a 3.5 mg cm−2 catalyst loading for Fe–N–C (blue stars) in the cathode. b, H2/O2 fuel cell polarization (solid symbols and left axis) and power density (hollow symbols and right axis) plots of the Pt-Fe-N-C cathode before cycling (black) and after 100,000 potential cycles (red) between 0.6 and 0.95 V. c,d, Current density as a function of time for Pt-Fe-N-C with a 0.015 mgPt cm−2 loading at 0.6 V in H2/O2 and H2/air environments (c) and fluoride concentration in water collected in the fuel cells using the Pt/C, Fe–N–C and Pt-Fe-N-C catalysts in the cathode during a potential hold at 0.6 V in a H2/air environment (d). For all the fuel cells tests, the membrane was Nafion HP, temperature 80 °C, relative humidity 100% and anode loading 0.1 mgPt cm–2. The H2/O2 fuel cell polarization curves were recorded at the H2/O2 flow rates of 300 or 300 ml min–1, absolute pressure of 1.5 baranode and 2.5 barcathode. The chronoamperometric measurements were at a discharge voltage of 0.6 V in H2/air or H2/O2 flow rates of 100 or 200 ml min–1 and 1 bar absolute pressure for both anode and cathode.
