Catalyst Layer Composition Effects in Proton Exchange Membrane Water Electrolysis

ACS electrochemistry., vol. 2, pp. 2208–2220

Abstract

Abstract The increasing demand for hydrogen necessitates reducing the capital cost of proton exchange membrane water electrolyzers (PEMWEs). A key approach is to reduce iridium loading while maintaining the high performance and durable operation. This requires optimization of the catalyst layer composition and minimization of interfacial contact resistance with the porous transport layer (PTL). This study investigates the effects of varying anode and cathode catalyst layer compositions on short-term and long-term performance of PEMWEs. The impact of reducing the IrOx loading from 1.0 to 0.5 mg∙cm–2, decreasing the anode ionomer content to 50%, and reducing the cathode ionomer content to 50% was evaluated. Performance was assessed through comparison of the Tafel slope, Tafel constant, charge transfer resistance, and ohmic resistance. The results indicate that performance losses were significantly reduced using a PTL with a high contact area when IrOx loading was reduced by 50%. However, reducing anode loading or ionomer content decreased catalyst layer thickness and ohmic resistance but slightly increased the Tafel constant. During long-term operation, no significant difference between the cell voltages was observed, attributed to higher irreversible losses that occurred with 0.5 mg∙cm–2 loading. In contrast, 50% reduction in cathode ionomer content led to significant improvement in performance, evidenced by reduced kinetic and ohmic losses in both short- and long-term operations.

Authors 13

1. Niklas L. Wolf Aachen

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich , , ,

   RWTH Aachen University , , ,

2. Fabian Meyer Aachen

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich , , ,

   RWTH Aachen University , , ,

3. Osmane Camara Aachen

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich , , ,

   RWTH Aachen University , , ,

4. Jialiang Liu Aachen

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich , , ,

   RWTH Aachen University , , ,

5. Kiran Kiran

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich , , ,

6. Francesco Bàrtoli

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich , , ,

7. Kristina Froehlich

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich , , ,

8. Shibabrata Basak

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich , , ,

9. Ali Javed

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich , , ,

10. Hans Kungl

    Forschungszentrum Jülich

    Affiliation as printed

    Forschungszentrum Jülich , , ,

11. André Karl

    Forschungszentrum Jülich

    Affiliation as printed

    Forschungszentrum Jülich , , ,

12. Eva Jodat

    Forschungszentrum Jülich

    Affiliation as printed

    Forschungszentrum Jülich , , ,

13. Rüdiger‐A. Eichel Aachen

    Forschungszentrum Jülich · RWTH Aachen University

    Affiliation as printed

    Forschungszentrum Jülich , , ,

    RWTH Aachen University , , ,