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

Abstract

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 mgMEA 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 hours 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 hours. 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.

Towards Replacing Titanium with Copper in the Bipolar Plates for Proton Exchange Membrane Water Electrolysis

“…Moreover, PEMWE can operate at variable current densities, making them suitable for connection with renewable energy sources [ 2 , 3 , 4 ]. The main disadvantage of the PEMWE consists in the harsh environment inside an operating electrolyzer, in particular the high temperature and electrochemical potential, as well as strong acidic conditions at the anode side, which implies significant corrosion problems of the stack components [ 5 , 6 ] and also degradation and durability issues of the membrane-electrode assembly [ 7 , 8 , 9 ] due to membrane thinning and both anode and cathode catalyst dissolution [ 10 , 11 ]. Titanium is currently used to manufacture bipolar plates (BPP) and porous transport layers (PTL) at the anode side, involving high costs for the PEM electrolyzer manufacturing process [ 12 ].…”

Essentials of High Performance Water Electrolyzers – From Catalyst Layer Materials to Electrode Engineering

“…Figure 9B,C shows the polarization curves and durability test data of catalyst layers with 0.3 mg IrRu cm −2 loading. [120] A cell with a 50 µm thin membrane achieved 1.3 A cm −2 at 1.6 V, corresponding to an Ir-SP of 9.2 kW g Ir −1 or an IrRu-SP of 6.4 kW g IrRu −1 if taking Ru into account. The cell showed a degradation rate of 20 µV h −1 during the hold of a relatively high current at 4 A cm −2 for 3500 h. As can be seen in Figure 9D, the cell voltage was almost constant during the last 2500 h test period.…”

“…Considering both durability and activity, the alloyed Ir 0.7 Ru 0.3 O 2 [120] is very promising with Ir-SP of 9.2 kW g Ir −1…”

“…C,D) Performance and durability of the cells using Ir 0.7 Ru 0.3 O 2 catalyst with a 50 µm thin membrane with and without recombination catalyst. Reproduced with permission [120]. Copyright 2020, Elsevier.…”

Numerical simulation of parameter change in a proton exchange membrane electrolysis cell based on a dynamic model

“…The proton exchange membrane electrolysis cell (PEMEC) consists of multi-scale structure, and involves multiphysical processes in operation. In the past decades, critical issues associated with performance, 3,4 durability, 5,6 and cost 7,8 have been investigated. Some studies about the effect of structure and materials on the performance of PEMEC have been conducted, such as catalyst, PEM, gas diffusion layer (GDL), and bipolar plate (BP).…”