Diffusion layer

Catalysis

Sediment

Engineering

Electrochemistry

Materials science

Chromatography

Deposition (geology)

Fuel cells

Biochemistry

Inorganic chemistry

Chemical engineering

Mass transfer

Geology

Dissolution

Physical chemistry

Paleontology

Thermodynamics

Physics

Nanotechnology

Organic chemistry

Membrane

Diffusion

Mass transfer coefficient

Gas diffusion electrode

Aqueous solution

Inductively coupled plasma mass spectrometry

Analytical Chemistry (journal)

Mass spectrometry

Chemistry

Electrode

Platinum

Angewandte Chemie International Edition

Pt dissolution has already been intensively studied in aqueous model systems and many mechanistic insights have been gained. Nevertheless, transfer of new knowledge to real‐world fuel cell systems is still a significant challenge. To close this gap, we present a novel in situ method combining a gas diffusion electrode (GDE) half‐cell with inductively coupled plasma mass spectrometry (ICP‐MS). With this setup, Pt dissolution in realistic catalyst layers and the transport of dissolved Pt species through Nafion membranes were evaluated directly. We observed that 1) specific Pt dissolution increased significantly with decreasing Pt loading, 2) in comparison to experiments on aqueous model systems with flow cells, the measured dissolution in GDE experiments was considerably lower, and 3) by adding a membrane onto the catalyst layer, Pt dissolution was reduced even further. All these phenomena are attributed to the varying mass transport conditions of dissolved Pt species, influencing re‐deposition and equilibrium potential.

Platinum Dissolution in Realistic Fuel Cell Catalyst Layers