1. Coralloid-Pt nanodendrites decorated nanoporous gold films with exceptional ORR performance and ab initio DFT studies.
- Author
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Si, Conghui, Yan, Xuejiao, Lu, Qifang, Guo, Enyan, Luo, Jing, Yang, Zhou, Zhang, Zhonghua, and Chen, Xiaoting
- Subjects
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GOLD films , *GOLD nanoparticles , *DENSITY functional theory , *POLAR effects (Chemistry) , *OXYGEN reduction , *FERMI level - Abstract
Coralloid-Pt nanodendrites decorated nanoporous gold films (NPG-Ptx) were fabricated through underpotential deposition/in-situ reduction replacement (UPD/IRR) strategy and exhibit significantly enhanced ORR activities. Ab initio density functional theory (DFT) studies further demonstrate the ORR mechanism of NPG-Ptx. [Display omitted] • Coralloid-Pt nanodendrites decorated nanoporous gold films (NPG-Ptx) were fabricated through underpotential deposition/in-situ reduction replacement (UPD/IRR) strategy. • The NPG-Ptx (x = 1 ∼ 4) exhibit significantly enhanced ORR activities in acidic media. • The DFT studies demonstrate the ORR mechanism and rate-determining step of NPG-Ptx follow the free energy diagrams. • The PDOS results indicate a relatively stronger O 2 reaction capacity on Pt side than Pt top. Deposition of trace amounts of Pt onto nanoporous gold ligaments (NPG-Pt) has demonstrated promising performance of low-Pt electrocatalysts for oxygen reduction reaction (ORR); however, improving the activity of ORR remains challenging because of the difficulty in understanding the electronic effect between Pt and NPG as well as the absence of ORR mechanism studies on NPG-Pt. Here we show that NPG-Ptx (x = 1 ∼ 4), unique coralloid-Pt nanodendrites decorated nanoporous gold films through underpotential deposition/in-situ reduction replacement (UPD/IRR) strategy, exhibit significantly enhanced ORR activities. Among them, NPG-Pt3 exhibits the best ORR activity compared with the others and Pt/C in acidic media. Density functional theory (DFT) studies demonstrate the ORR mechanism and rate-determining step of NPG-Ptx follow the free energy diagrams. Furthermore, the projected density of state (PDOS) results reveal a relatively weaker O 2 reaction capacity on the top side of Pt (Pt top) than the side site (Pt side) for NPG-Ptx. The increase of d -band center for NPG-Ptx pushes up the energy of the antibonding state above the Fermi level, and then the backflow of electrons into the system makes the energy more stable, optimizing the ORR activity. These results provide new inspirations for the development of low-Pt electrocatalysts for energy technologies in a rational manner. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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