Single-Iron Site Catalysts with Self-Assembled Dual-size Architecture and Hierarchical Porosity for Proton-Exchange Membrane Fuel Cells

Zhao, Xiaolin; Yang, Xiaoxuan; Wang, Maoyu; Hwang, Sooyeon; Karakalos, Stavros; Chen, Mengjie; Qiao, Zhi; Wang, Lei; Liu, Bin; Ma, Qing; Cullen, David A.; Su, Dong; Yang, Haipeng; Zang, Hong‐Ying; Feng, Zhenxing; Wu, Gang

doi:10.1016/j.apcatb.2020.119400

“…It would shed light on understanding the synthesis‐structure‐property correlation for rational catalyst design with further enhanced activity, selectivity, and stability. The developed model system of single metal site catalysts can study other advanced electrocatalysis, such as oxygen [56, 57] and nitrogen reactions [58–60] …”

Section: Resultsmentioning

confidence: 99%

“…Thec omprehensive understanding of morphological and intrinsic factors for designing Fe-N-C catalysts led to encouraging CO2RR activity with j CO of 25 mA cm À2 at À0.8 Vv s. RHE as well as CO FEs above 90 %i nab road operation potential range testing in an H-cell using 0.1 MK HCO 3 Angewandte Chemie Forschungsartikel electrolyte.Given ZIF-8 precursors popularity for preparing atomically dispersed M-N-C catalysts,w eb elieve that this work can be further expanded to other single metal site catalysts (e.g., Ni, Mn, Co,Cu, or Cr) for the CO2RR. [37,55] It would shed light on understanding the synthesis-structureproperty correlation for rational catalyst design with further enhanced activity,s electivity,a nd stability.T he developed model system of single metal site catalysts can study other advanced electrocatalysis,s uch as oxygen [56,57] and nitrogen reactions. [58][59][60]…”

Section: Discussionmentioning

confidence: 99%

Engineering Atomically Dispersed FeN₄ Active Sites for CO₂ Electroreduction

Adli

¹

,

Shan

²

,

Hwang

³

et al. 2020

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Atomically dispersed FeN4 active sites have exhibited exceptional catalytic activity and selectivity for the electrochemical CO2 reduction reaction (CO2RR) to CO. However, the understanding behind the intrinsic and morphological factors contributing to the catalytic properties of FeN4 sites is still lacking. By using a Fe‐N‐C model catalyst derived from the ZIF‐8, we deconvoluted three key morphological and structural elements of FeN4 sites, including particle sizes of catalysts, Fe content, and Fe−N bond structures. Their respective impacts on the CO2RR were comprehensively elucidated. Engineering the particle size and Fe doping is critical to control extrinsic morphological factors of FeN4 sites for optimal porosity, electrochemically active surface areas, and the graphitization of the carbon support. In contrast, the intrinsic activity of FeN4 sites was only tunable by varying thermal activation temperatures during the formation of FeN4 sites, which impacted the length of the Fe−N bonds and the local strains. The structural evolution of Fe−N bonds was examined at the atomic level. First‐principles calculations further elucidated the origin of intrinsic activity improvement associated with the optimal local strain of the Fe−N bond.

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“…Thec omprehensive understanding of morphological and intrinsic factors for designing Fe-N-C catalysts led to encouraging CO2RR activity with j CO of 25 mA cm À2 at À0.8 Vv s. RHE as well as CO FEs above 90 %i nab road operation potential range testing in an H-cell using 0.1 MK HCO 3 electrolyte.Given ZIF-8 precursors popularity for preparing atomically dispersed M-N-C catalysts,w eb elieve that this work can be further expanded to other single metal site catalysts (e.g., Ni, Mn, Co,Cu, or Cr) for the CO2RR. [37,55] It would shed light on understanding the synthesis-structureproperty correlation for rational catalyst design with further enhanced activity,s electivity,a nd stability.T he developed model system of single metal site catalysts can study other advanced electrocatalysis,s uch as oxygen [56,57] and nitrogen reactions. [58][59][60]…”

Section: Discussionmentioning

confidence: 99%

Engineering Atomically Dispersed FeN₄ Active Sites for CO₂ Electroreduction

Adli

¹

,

Shan

²

,

Hwang

³

et al. 2020

Self Cite

View full text Add to dashboard Cite

Atomically dispersed FeN4 active sites have exhibited exceptional catalytic activity and selectivity for the electrochemical CO2 reduction reaction (CO2RR) to CO. However, the understanding behind the intrinsic and morphological factors contributing to the catalytic properties of FeN4 sites is still lacking. By using a Fe‐N‐C model catalyst derived from the ZIF‐8, we deconvoluted three key morphological and structural elements of FeN4 sites, including particle sizes of catalysts, Fe content, and Fe−N bond structures. Their respective impacts on the CO2RR were comprehensively elucidated. Engineering the particle size and Fe doping is critical to control extrinsic morphological factors of FeN4 sites for optimal porosity, electrochemically active surface areas, and the graphitization of the carbon support. In contrast, the intrinsic activity of FeN4 sites was only tunable by varying thermal activation temperatures during the formation of FeN4 sites, which impacted the length of the Fe−N bonds and the local strains. The structural evolution of Fe−N bonds was examined at the atomic level. First‐principles calculations further elucidated the origin of intrinsic activity improvement associated with the optimal local strain of the Fe−N bond.

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“…In this work, the CVD‐derived Fe‐N‐C catalyst has demonstrated promising stability in MEAs, relative to other reported catalysts [57] . Engineering carbon structures with enhanced corrosion resistance and optimized electrode structures are imperative to address further the stability challenge of the Fe‐N‐C catalyst in MEAs [62, 63] …”

Section: Resultsmentioning

confidence: 96%

“…[57] Engineering carbon structures with enhanced corrosion resistance and optimized electrode structures are imperative to address further the stability challenge of the Fe-N-C catalyst in MEAs. [62,63]…”

Section: Catalytic Performance For the Orrmentioning

confidence: 99%

Chemical Vapor Deposition for Atomically Dispersed and Nitrogen Coordinated Single Metal Site Catalysts

Liu

¹

,

Wang

²

,

Yang

³

et al. 2020

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Atomically dispersed and nitrogen coordinated single metal sites (M-N-C,M= Fe,Co, Ni, Mn) are the popular platinum group-metal (PGM)-free catalysts for many electrochemical reactions.Traditional wet-chemistry catalyst synthesis often requires complex procedures with unsatisfied reproducibility and scalability.H ere,w er eport af acile chemical vapor deposition (CVD) strategy to synthesize the promising M-N-C catalysts.T he deposition of gaseous 2-methylimidazole onto M-doped ZnO substrates,f ollowed by an in situ thermal activation, effectively generated single metal sites well dispersed into porous carbon. In particular,a no ptimal CVDderived Fe-N-C catalyst exclusively contains atomically dispersed FeN 4 sites with increased Fe loading relative to other catalysts from wet-chemistry synthesis.T he catalyst exhibited outstanding oxygen-reduction activity in acidic electrolytes, which was further studied in proton-exchange membrane fuel cells with encouraging performance.

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Single-Iron Site Catalysts with Self-Assembled Dual-size Architecture and Hierarchical Porosity for Proton-Exchange Membrane Fuel Cells

Cited by 107 publications

References 57 publications

Engineering Atomically Dispersed FeN₄ Active Sites for CO₂ Electroreduction

Engineering Atomically Dispersed FeN₄ Active Sites for CO₂ Electroreduction

Engineering Atomically Dispersed FeN₄ Active Sites for CO₂ Electroreduction

Chemical Vapor Deposition for Atomically Dispersed and Nitrogen Coordinated Single Metal Site Catalysts

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Single-Iron Site Catalysts with Self-Assembled Dual-size Architecture and Hierarchical Porosity for Proton-Exchange Membrane Fuel Cells

Cited by 107 publications

References 57 publications

Engineering Atomically Dispersed FeN4 Active Sites for CO2 Electroreduction

Engineering Atomically Dispersed FeN4 Active Sites for CO2 Electroreduction

Engineering Atomically Dispersed FeN4 Active Sites for CO2 Electroreduction

Chemical Vapor Deposition for Atomically Dispersed and Nitrogen Coordinated Single Metal Site Catalysts

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Product

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Engineering Atomically Dispersed FeN₄ Active Sites for CO₂ Electroreduction

Engineering Atomically Dispersed FeN₄ Active Sites for CO₂ Electroreduction

Engineering Atomically Dispersed FeN₄ Active Sites for CO₂ Electroreduction