Durability of a recombination catalyst-based membrane-electrode assembly for electrolysis operation at high current density

• A PtCo recombination catalyst is successfully integrated in a PEM electrolysis cell. • Voltage efficiency of ~80% is achieved at 4 A cm −2 in a durability test of 3500 h. • Performance losses of 9 μV/h are recorded in a durability test at 4 A cm −2 . • A thin (50 µm) membrane was used along with the recombination catalyst. • Low catalyst loadings (0.6 mg MEA PGM cm −2 ) were used. Hydrogen production through polymer electrolyte membrane water electrolysis was investigated at high current density (4 A cm −2 ). A PtCo recombination catalyst-based membrane-electrode assembly (MEA) was assessed in terms of performance, efficiency and durability. The electrolysis cell consisted of a thin (50 µm) perfluorosulfonic acid membrane and low platinum group metals (PGM) catalyst loadings (0.6 mg MEA PGM cm −2 ). An unsupported PtCo catalyst was successfully integrated in the anode. A composite catalytic layer made of IrRuOx and PtCo assisted both oxygen evolution and oxidation of hydrogen permeated through the membrane. The cell voltage for the recombination catalyst-based MEA was about 30 mV lower than the bare MEA during a 3500 h durability test. The modified MEA showed low performance losses during 3500 h operation at high current density (4 A cm −2 ) with low catalyst loadings. A decay rate of 9 µV/h was observed in the last 1000 h. These results are promising for decreasing the capital costs of polymer electrolyte membrane electrolysers. Moreover, the stable voltage efficiency of about 80% vs. the high heating value (HHV) of hydrogen at 4 A cm −2 , here achieved, appears very promising to decrease operating expenditures.