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The oxygen reduction reaction (ORR) is a critical process in energy conversion systems, influencing the efficiency and performance of various devices such as fuel cells, batteries, and electrolyzers. Perovskite-supported metal materials (metal/perovskite) offer several advantages as ORR electrocatalysts, including strong metal-support interactions, oxygen vacancy formation in the perovskite lattice, and synergistic triple-phase boundary (TPB) activity at the interface. Despite their significance, the mechanistic understanding of ORR on metal/perovskite catalysts remains incomplete, particularly at metal/perovskite interfaces. This study investigates ORR on BaZrO3 (BZO) perovskite-supported metal clusters (Pt or Ag) using density functional theory (DFT) to unravel critical insights into charge redistribution at the metal/BZO interface. Energy profiles for elemental steps along two different ORR pathways—oxygen adsorption on the metal cluster surface and direct oxygen adsorption at the TPB—were calculated to explore the effects of different active sites. The results provide a deeper understanding of ORR on metal/perovskite catalysts, emphasizing the role of interfacial interactions and pathway-dependent reaction mechanisms. This work paves the way for guiding the design of high-performance electrocatalysts for ORR in terms of composition, interface design, and local environment modification for a broad range of energy applications.
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Advanced electrocatalysts for fuel cells: Evolution of active sites and synergistic properties of catalysts and carrier materials
Abstract Proton exchange‐membrane fuel cell (PEMFC) is a clean and efficient type of energy storage device. However, the sluggish reaction rate of the cathode oxygen reduction reaction (ORR) has been a significant problem in its development. This review reports the recent progress of advanced electrocatalysts focusing on the interface/surface electronic structure and exploring the synergistic relationship of precious‐based and non‐precious metal‐based catalysts and support materials. The support materials contain non‐metal (C/N/Si, etc.) and metal‐based structures, which have demonstrated a crucial role in the synergistic enhancement of electrocatalytic properties, especially for high‐temperature fuel cell systems. To improve the strong interaction, some exciting synergistic strategies by doping and coating heterogeneous elements or connecting polymeric ligands containing carbon and nitrogen were also shown herein. Besides the typical role of the crystal surface, phase structure, lattice strain, etc., the evolution of structure‐performance relations was also highlighted in real‐time tests. The advanced in situ characterization techniques were also reviewed to emphasize the accurate structure‐performance relations. Finally, the challenge and prospect for developing the ORR electrocatalysts were concluded for commercial applications in low‐ and high‐temperature fuel cell systems.
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- Award ID(s):
- 2102482
- PAR ID:
- 10513885
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Exploration
- Volume:
- 5
- Issue:
- 1
- ISSN:
- 2766-8509
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Oxygen reduction reaction (ORR) is an electrochemical reaction in which dissolved oxygen in an electrolyte is reduced to OH−/H2O when receiving electrons. This reaction plays a crucial role in shaping the efficiency of both metal–air batteries and fuel cells, and precious metals are the dominant catalysts carrying out the ORR in their cathodes. However, how to manipulate the electronic structure of precious metals as active sites to further promote ORR performance and maximize the utilization rate is still under development. Metal oxide serves as suitable and promising support that can strongly interact with precious metals for both activity and durability enhancement. Herein, we present recent research updates on strong precious metal–metal oxide interaction (SPMMOI) utilized in ORR. We start by introducing the background of ORR, the issues to be solved, and its practical applications followed by a thorough discussion of the reaction mechanism and comprehensive evaluation protocols of performance. We then provide a complete understanding of the working principle of SPMMOI and highlight the related advances. Finally, we summarize the merits of the precious metal–metal oxide system and propose the research direction as well as some urgent problems to be addressed in the future.more » « less
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