Implementing PGM-free electrocatalysts in high-temperature polymer electrolyte membrane fuel cells

Polymer Electrolyte Membrane Fuel Cells (PEMFCs) face numerous challenges, involving the membrane nature and the active material for the cathodic reaction. A way to achieve more efficient PEMFCs is to increase their operating temperature above 373 K: High-Temperature PEMFCs (HT-PEMFCs). In this communication, we introduce for the first time the use of platinum group metal-free electrocatalysts (PGM-free) for oxygen reduction reaction (ORR) in HT-PEMFC, namely an iron‑nitrogen‑carbon (Fe-N-C) electrocatalyst synthesized by the sacrificial support method and discuss their performances. A cell voltage of 0.43 V was observed at 0.2 A cmgeo−2, this activity being greatly improved by increasing the back-pressure of the PEMFC (from 0.0 to 3.0 × 105 Pa), reaching a polarization of 0.65 V at 0.2 A cmgeo−2 (at 433 K, O2 at the cathode), thus proving that the main limitations of the HT-PEMFC with a Fe-N-C cathode were not induced by the intrinsic activity of the electrocatalyst, but by the transport of the oxygen throughout the electrocatalyst structure. [Display omitted] •Fe-N-C electrocatalyst was synthesized by the sacrificial support method.•The F Fe-N-C electrocatalyst was characterized in single-cell configuration in a high temperature PEMFC.•At 0.2 A cmgeo−2, a polarization of 0.43 V was observed without back-pressure and polarization of 0.65 V with a back-pressure of 3.0 × 105 Pa.