Abstract
It is shown that producing PrBaCo2O5+δ and Ba0.5Sr0.5Co0.8Fe0.2O2+δ
nanoparticle by a scalable synthesis method leads to high mass
activities for the oxygen evolution reaction (OER) with outstanding
improvements by 10× and 50×, respectively, compared to those prepared
via the state‐of‐the‐art synthesis method. Here, detailed comparisons at
both laboratory and industrial scales show that Ba0.5Sr0.5Co0.8Fe0.2O2+δ appears to be the most active and stable perovskite catalyst under alkaline conditions, while PrBaCo2O5+δ
reveals thermodynamic instability described by the density‐functional
theory based Pourbaix diagrams highlighting cation dissolution under OER
conditions. Operando X‐ray absorption spectroscopy is used in
parallel to monitor electronic and structural changes of the catalysts
during OER. The exceptional BSCF functional stability can be correlated
to its thermodynamic meta‐stability under OER conditions as highlighted
by Pourbaix diagram analysis. BSCF is able to dynamically
self‐reconstruct its surface, leading to formation of Co‐based
oxy(hydroxide) layers while retaining its structural stability.
Differently, PBCO demonstrates a high initial OER activity while it
undergoes a degradation process considering its thermodynamic
instability under OER conditions as anticipated by its Pourbaix diagram.
Overall, this work demonstrates a synergetic approach of using both
experimental and theoretical studies to understand the behavior of
perovskite catalysts.
Original language | English |
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Article number | 1804355 |
Journal | Advanced Functional Materials |
Volume | 28 |
Issue number | 45 |
Number of pages | 10 |
ISSN | 1616-301X |
DOIs | |
Publication status | Published - 2018 |
Keywords
- Electrolysis
- Electrolyzer
- Pourbaix diagram
- Stability
- X-ray absorption spectroscopy