In situ electrochemical grazing incidence small angle X-ray scattering: From the design of an electrochemical cell to an exemplary study of fuel cell catalyst degradation

JOURNAL OF POWER SOURCES

卷:477

Article

Bogar, Marco^1,2  Khalakhan, Ivan³  Gambitta, Alessandro⁴  Yakovlev, Yurii³  Amenitsch, Heinz² 

[1] Elettra Sincrotrone, CERIC ERIC, SS 14 Km 163-5, I-34149 Trieste, Italy

[2] Graz Univ Technol, Inst Inorgan Chem, Stremayrgasse 9, A-8010 Graz, Austria

[3] Charles Univ Prague, Fac Math & Phys, Dept Surface & Plasma Sci, V Holesovickach 2, Prague 18000 8, Czech Republic

[4] Elettra Sincrotrone Trieste, SS 14 Km 163-5, I-34149 Basovizza, Italy

关键词: Fuel cells;    Electrochemistry;    Grazing incidence small angle X-ray scattering;    Ostwald ripening;    Nanoparticles;    Catalyst layer;   

DOI  :  10.1016/j.jpowsour.2020.229030

来源: Elsevier

【 摘 要 】

Nowadays, electrochemistry has a considerable technological impact, involving fuel cells, super capacitors and batteries. These devices are based on complex architectures, which complicates monitoring their evolution in situ under operating conditions to reveal the reasons for reduced lifetime and performances. Here, we present a design of a multipurpose electrochemical cell for grazing incidence small and wide angle X-ray scattering (GISAXS and GIWAXS) where the environment for operating conditions can be recreated. We focus on proton exchange membrane fuel cells (PEMFCs) which operational conditions are simulated by means of potentiodynamic-based accelerated stress tests, applied to a thin film of Pt nanoparticles representing a model system of a benchmark catalyst. Two different upper potentials are used to mimic fuel cell operating conditions: at 1.0 V RHE the catalyst film preserves its initial morphology, while at 1.5 V RHE (simulating fuel cell start-up/ shut-down cycles) significant coarsening has been observed. The initial dimension of the Pt particles of 4.0 nm increases to 8.7 nm due to the predominant process of coalescence and final Ostwald ripening. In parallel, the distance between the particles increases, the catalyst film (9 nm thick) becomes thinner at first and exhibit a higher roughness at the end.

【 授权许可】

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