Exploring Durable Single-Atom Catalysts for Proton Exchange Membrane Fuel Cells

Wan, Xin; Shui, Jianglan

doi:10.1021/acsenergylett.2c00473

Cited by 72 publications

(61 citation statements)

References 97 publications

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“…In view of this, many catalysts would be covered by oxygen species (O/OH) under the OER working potentials. − For this end, we considered that the equilibrium phase of the Co-N 4 catalyst was covered by oxygen species (O/OH), forming the HO-/O-Co-N 4 configurations (such as HO/O-Co-N 4 -G N , HO/O-Co-N 4 -P N , and HO/O-Co-N 4 -C) in Figure S29. DFT theoretical calculations were further performed to investigate the effect of preadsorbed oxygen species (HO/O) on the OER performance of Co-N 4 configurations.…”

Section: Resultsmentioning

confidence: 99%

Modulation of Ligand Fields in a Single-Atom Site by the Molten Salt Strategy for Enhanced Oxygen Bifunctional Activity for Zinc-Air Batteries

Wang

Jing

et al. 2022

ACS Nano

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Achieving full utilization of active sites and optimization of the electronic structure of metal centers is the key to improving the intrinsic activity of single-atom catalysts (SACs) but still remains a challenge to date. Herein, a versatile molten saltassisted pyrolysis strategy was developed to construct ultrathin, porous carbon nanosheets supported Co SACs. Molten salts are capable of inducing the formation of a Co singleatom and porous graphene-like carbon, which facilitates full exposure of the active center and simultaneously endows the Co SACs with abundant defective Co-N 4 configurations. The reported Co SACs deliver an excellent bifunctional activity and good stability for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Moreover, metal-air batteries (MABs) assembled with the Co SACs as air electrode also deliver excellent performance with high power densities of 160 mW•cm −2 , large capacities of 760 mAh•g −1 , and superior long-term charge/discharge stability, outperforming those of commercial Pt/C+RuO 2 . DFT theoretical calculation results show that the defects in the second coordination shell (CS) of Co SACs promote desorption of the OH* intermediate for the ORR and facilitate deprotonation of OH* for the OER, which can serve as the favorable active site for oxygen bifunctional catalysts. Our work provides an efficient strategy for the preparation of SACs with fully exposed active centers and optimized electronic structures.

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Section: Resultsmentioning

confidence: 99%

Modulation of Ligand Fields in a Single-Atom Site by the Molten Salt Strategy for Enhanced Oxygen Bifunctional Activity for Zinc-Air Batteries

Wang

Jing

et al. 2022

ACS Nano

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“…However, considering the failure problem in isolation is not possible since the degradation behaviors affect each other. 25 For example, carbon corrosion spoils the structure of the carbon surface, leading to the demetallation of FeN 4 active sites. The leached Fe ions carry out proton exchange with the Nafion ionomer to reduce the proton conductivity.…”

Section: Resultsmentioning

confidence: 99%

New insights into degradation of Fe–N–C catalyst layers: ionomer decomposition

Zhang

Chen

et al. 2022

J. Mater. Chem. A

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“…The FeN 4 C 12 site shows better ORR intrinsic activity but poor stability to the FeN 4 C 10 site. The FeN 4 C 12 site is irreversibly oxidized to Fe 2 O 3 in ORR progress, and the FeN 4 C 10 site has stronger resistance to Fe atom stripping and oxidation ( Kramm et al, 2012 ; Zitolo et al, 2015 ; Wan and Shui, 2022 ). Therefore, regulating the ratio of the two type sites in the Fe-N-C catalyst to balance the activity and stability is very important.…”

Section: The Structure–activity Relationship Between Defects and Elec...mentioning

confidence: 99%

Defective nanomaterials for electrocatalysis oxygen reduction reaction

Mao

Tang

et al. 2022

Front. Chem.

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The difficulties in O2 molecule adsorption/activation, the cleavage of the O–O bond, and the desorption of the reaction intermediates at the surface of the electrodes make the cathodic oxygen reduction reaction (ORR) for fuel cells show extremely sluggish kinetics. Thus, it is important to the exploitation of highly active and stable electrocatalysts for the ORR to promote the performance and commercialization of fuel cells. Many studies have found that the defects affect the electron and the geometrical structure of the catalyst. The catalytic performance is enhanced by constructing defects to optimize the adsorption energy of substrates or intermediates. Unfortunately, still many issues are poorly recognized, such as the effect of defects (types, contents, and locations) in catalytic performance is unclear, and the catalytic mechanism of defective nanomaterials is lacking. In this review, the defective electrocatalysts divided into noble and non-noble metals for the ORR are highlighted and summarized. With the assistance of experimental results and theoretical calculations, the structure–activity relationships between defect engineering and catalytic performance have been clarified. Finally, after a deeper understanding of defect engineering, a rational design for efficient and robust ORR catalysts for PEMFCs is further guided.

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Exploring Durable Single-Atom Catalysts for Proton Exchange Membrane Fuel Cells

Cited by 72 publications

References 97 publications

Modulation of Ligand Fields in a Single-Atom Site by the Molten Salt Strategy for Enhanced Oxygen Bifunctional Activity for Zinc-Air Batteries

Modulation of Ligand Fields in a Single-Atom Site by the Molten Salt Strategy for Enhanced Oxygen Bifunctional Activity for Zinc-Air Batteries

New insights into degradation of Fe–N–C catalyst layers: ionomer decomposition

Defective nanomaterials for electrocatalysis oxygen reduction reaction

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