Atomic‐Level Modulation of Electronic Density at Cobalt Single‐Atom Sites Derived from Metal–Organic Frameworks: Enhanced Oxygen Reduction Performance

Chen, Yuanjun; Gao, Rui; Ji, Shufang; Li, Haijing; Tang, Kun; Jiang, Peng; Hu, Haibo; Zhang, Zedong; Hao, Haigang; Qu, Qingyun; Liang, Xiao; Chen, Wenxing; Dong, Juncai; Wang, Dingsheng; Li, Yadong

doi:10.1002/anie.202012798

Cited by 534 publications

(269 citation statements)

References 58 publications

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“…These results partially demonstrate that HBE of single-atom Pt—although is one of the influential factors—is not critical for the single-atom catalytic activity in alkaline HER 9 . Considering the sluggish water dissociation in the Volmer and Heyrovsky steps (H 2 O + e − → H* + OH − and H* + H 2 O + e − → H 2 + OH − , * represents an adsorption site) during alkaline HER 38 , we then focused on the contribution of water dissociation.…”

Section: Resultsmentioning

confidence: 99%

Electronic metal–support interaction modulates single-atom platinum catalysis for hydrogen evolution reaction

et al. 2021

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Tuning metal–support interaction has been considered as an effective approach to modulate the electronic structure and catalytic activity of supported metal catalysts. At the atomic level, the understanding of the structure–activity relationship still remains obscure in heterogeneous catalysis, such as the conversion of water (alkaline) or hydronium ions (acid) to hydrogen (hydrogen evolution reaction, HER). Here, we reveal that the fine control over the oxidation states of single-atom Pt catalysts through electronic metal–support interaction significantly modulates the catalytic activities in either acidic or alkaline HER. Combined with detailed spectroscopic and electrochemical characterizations, the structure–activity relationship is established by correlating the acidic/alkaline HER activity with the average oxidation state of single-atom Pt and the Pt–H/Pt–OH interaction. This study sheds light on the atomic-level mechanistic understanding of acidic and alkaline HER, and further provides guidelines for the rational design of high-performance single-atom catalysts.

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Section: Resultsmentioning

confidence: 99%

Electronic metal–support interaction modulates single-atom platinum catalysis for hydrogen evolution reaction

et al. 2021

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“…The peak at 2.41Å could be ascribed to Pt-Pt bonds in Pt-SMO-Co 2 N NWs, of which intensity increased with extended electrochemical oxidation duration. To illustrate the evolution of Pt local structure more straightforwardly, the wavelet transform (WT) analysis was performed (Figure 2e and 2f ) 28 . The WT contour plots also showed the same trend as that of Fourier transformed Pt L-edge spectra.…”

Section: Resultsmentioning

confidence: 99%

Surface Microenvironment Optimization Induced Robust Oxygen Reduction for Neutral Zinc-Air Batteries

Liu

Han

Xia

et al. 2021

Preprint

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Neutral zinc-air batteries (ZABs) are promising candidates for the next-generation power devices with considerably elongated lifetime comparing to conventional alkaline ZABs. However, neutral cathodic oxygen reduction reaction is seriously limited by the mass transfer efficiency of hydroxyl due to insufficient interfacial chemical potential-gradient between catalytic layer and electrolyte. Herein, we highlight that electrochemical oxidation induced surface microenvironment optimization could realize optimal chemical potential-gradient around catalytic sites and bring outstanding neutral ORR activity. The electro-deposited sub-nano Pt decorated surface-microenvironment-optimized Co2N samples (denoted as Pt-SMO-Co2N NWs) possessed 92 mV and 365 mV lower overpotential than commercial Pt/C and pristine Co2N in 0.2 M PBS. As for neutral ZABs, Pt-SMO-Co2N NWs cathode delivers a power density of 67.9 mW*cm−2 and displays negligible decay after nearly 80 hours stability test at 20 mA*cm-2. In depth characterization proposes that remarkable performance improvement originates from optimized microenvironment which increases the surface chemical potential gradient and facilitates proton coupled electron transfer during ORR. We anticipated that such synergetic optimization of microenvironment and intrinsic activity of active sites is an effective strategy which may be extended the catalytic reactions beyond ORR.

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“…[ 35 ] DFT calculations indicate that the electronic density of Co SACs can be tailored through regulating coordinated atoms. [ 36 ] Chen et al. proposed that the coordinated S and P atoms can donate electrons to single‐atom Fe centers, resulting in Fe is less positive, which helps weaken the binding of adsorbed OH species.…”

Section: In Situ Xasmentioning

confidence: 99%

Operando XAS/SAXS: Guiding Design of Single‐Atom and Subnanocluster Catalysts

et al. 2021

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Single‐atom and subnanocluster catalysts (SSCs) represent a highly promising class of low‐cost materials with high catalytic activity and high atom‐utilization efficiency. However, SSCs are susceptible to undergo restructuring during the reactions. Exploring the active sites of catalysts through in situ characterization techniques plays a critical role in studying reaction mechanism and guiding the design of optimum catalysts. In situ X‐ray absorption spectroscopy/small‐angle X‐ray scattering (XAS/SAXS) is promising and widely used for monitoring electronic structure, atomic configuration, and size changes of SSCs during real‐time working conditions. Unfortunately, there is no detailed summary of XAS/SAXS characterization results of SSCs. The recent advances in applying in situ XAS/SAXS to SSCs are thoroughly summarized in this review, including the atomic structure and oxidation state variations under open circuit and realistic reaction conditions. Furthermore, the reversible transformation of single‐atom catalysts (SACs) to subnanoclusters/nanoparticles and the application of in situ XAS/SAXS in subnanoclusters are discussed. Finally, the outlooks in modulating the SSCs and developing operando XAS/SAXS for SSCs are highlighted.

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Atomic‐Level Modulation of Electronic Density at Cobalt Single‐Atom Sites Derived from Metal–Organic Frameworks: Enhanced Oxygen Reduction Performance

Cited by 534 publications

References 58 publications

Electronic metal–support interaction modulates single-atom platinum catalysis for hydrogen evolution reaction

Electronic metal–support interaction modulates single-atom platinum catalysis for hydrogen evolution reaction

Surface Microenvironment Optimization Induced Robust Oxygen Reduction for Neutral Zinc-Air Batteries

Operando XAS/SAXS: Guiding Design of Single‐Atom and Subnanocluster Catalysts

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