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Updated: Jun 13, 2025
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Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
18.1K
Designing bifunctional perovskite catalysts for the oxygen reduction and evolution reactions
Casey E Beall1, Emiliana Fabbri1, Adam H Clark1
1Paul Scherrer Institute (PSI) 5232 Villigen PSI Switzerland emiliana.fabbri@psi.ch.
EES Catalysis
|September 9, 2024
Summary
Developing stable bifunctional oxygen electrocatalysts for unified regenerative fuel cells (URFCs) is crucial. This study explores two strategies, incorporating active sites into perovskites or creating mixed composites, to enhance catalyst performance for oxygen reduction (ORR) and oxygen evolution (OER).
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Unified regenerative fuel cells (URFCs) require highly active and stable bifunctional oxygen electrocatalysts for efficient operation.
- Designing catalysts with high activity for both oxygen reduction (ORR) and oxygen evolution (OER) reactions, while maintaining stability under dynamic conditions, presents a significant challenge.
Purpose of the Study:
- To investigate two distinct strategies for developing advanced bifunctional oxygen electrocatalysts for URFC applications.
- To optimize catalyst performance by exploring single-phase perovskite structures and mixed composite approaches.
Main Methods:
- Synthesis of perovskite catalysts (Ba0.5Sr0.5Co0.8Mn0.2O3-, La0.5Ba0.25Sr0.25Co0.5Mn0.5O3-) and a mixed composite (BSCF/LSM).
- Evaluation of catalytic performance under conditions mimicking URFC operation, including response to alternating reducing and oxidizing potentials.
- Operando X-ray absorption spectroscopy (XAS) to elucidate the dynamic changes in metal oxidation states during ORR and OER.
Main Results:
- Both single-phase perovskites and mixed composites demonstrated potential as bifunctional oxygen electrocatalysts.
- Operando XAS revealed the dynamic redox behavior of Mn, Co, and Fe active sites during electrochemical reactions.
- Key catalyst physiochemical properties influencing performance were identified.
Conclusions:
- The study successfully demonstrates two viable strategies for designing bifunctional oxygen electrocatalysts.
- Understanding the dynamic oxidation states of active sites is critical for optimizing catalyst stability and activity.
- The findings provide valuable insights and design principles for future development of advanced electrocatalysts for URFCs.
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