Particle Size Effect on Platinum Dissolution: Practical Considerations for Fuel Cells

Sandbeck D, Inaba M, Quinson J, Bucher J, Zana A, Arenz M, Cherevko S (2020)

Publication Type: Journal article

Publication year: 2020

Journal

ACS Applied Materials and Interfaces American Chemical Society

Book Volume: 12

Pages Range: 25718-25727

Journal Issue: 23

DOI: 10.1021/acsami.0c02801

Abstract

The high costs of polymer membrane electrolyte fuel cells (PEMFCs) remain a roadblock for a competitive market with combustion engine vehicles. The PEMFC costs can be reduced by decreasing the size of Pt nanoparticles in the catalyst layer, thereby increasing the Pt dispersion and utilization. Furthermore, high-power performance loss due to O2 transport resistance is alleviated by decreasing the particle size and increasing dispersion. However, firm conclusions on how Pt particle size impacts durability remain elusive due to synthetic difficulties in exclusively varying single parameters (e.g., particle size and loading). Therefore, here the particle size of Pt nanoparticles was varied from 2.0 to 2.8 and 3.7 nm while keeping the loading constant (30 wt %) on a Vulcan support using the two-step surfactant-free toolbox method. By studying the electrochemical dissolution in situ using online inductively coupled plasma mass spectrometry (online ICP-MS), mass-specific dissolution trends are revealed and are attributed to particle-size-dependent changes in electrochemically active surface area. Such degradation trends are critical for the start/stop of PEMFCs and currently require the implementation of potential control systems in consumer vehicles. Additionally, shifts in the onset of anodic dissolution and also oxidation to more negative potentials with decreasing particle size were observed. These results indicate a similar mechanism of anodic dissolution related to place-exchange when moving from extended polycrystalline Pt to nanoparticle scales. The negative shifts in the onset as the particle size decreases highlight a practical limitation for PEMFCs during load/idle conditions: without further material improvements, which inhibit Pt dissolution, reduction in costs and improvement in high-power performance via increased Pt utilization and dispersion will not be possible by decreasing particle sizes further.

Authors with CRIS profile

Daniel Sandbeck Lehrstuhl für Elektrokatalyse (HIERN)

Involved external institutions

Universität Bern CH Switzerland (CH) University of Copenhagen DK Denmark (DK) Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE)

How to cite

APA:

Sandbeck, D., Inaba, M., Quinson, J., Bucher, J., Zana, A., Arenz, M., & Cherevko, S. (2020). Particle Size Effect on Platinum Dissolution: Practical Considerations for Fuel Cells. ACS Applied Materials and Interfaces, 12(23), 25718-25727. https://dx.doi.org/10.1021/acsami.0c02801

MLA:

Sandbeck, Daniel, et al. "Particle Size Effect on Platinum Dissolution: Practical Considerations for Fuel Cells." ACS Applied Materials and Interfaces 12.23 (2020): 25718-25727.

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