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Platinum-based nanocages with subnanometer-thick walls and well-defined, controllable facets

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Science  24 Jul 2015:
Vol. 349, Issue 6246, pp. 412-416
DOI: 10.1126/science.aab0801
  • Fig. 1 Structural and compositional analyses of Pt cubic nanocages.

    (A) TEM image of a typical sample. (B) HAADF-STEM image of an individual nanocage. (C) High-resolution HAADF-STEM image taken from the region boxed in (B), showing a wall thickness of six atomic layers. (D) EDS elemental mapping of Pt and Pd for two nanocages. Scale bar, 10 nm.

  • Fig. 2 Mechanistic details involved in the deposition and etching processes, and TEM images of the products obtained after etching for different periods of time.

    (A) Pt atoms deposited on the Pd surface may diffuse (“hop”) across the surface or substitute into the surface (DFT-calculated activation barriers are shown), leading to a mixed outer-layer composition. (B) Schematic of the major steps involved in the continuous dissolution of Pd atoms from a Pd@Pt4L cube to generate a Pt cubic nanocage. (C to F) TEM images of Pd@Pt4L cubes after Pd etching for (C) 0, (D) 10, (E) 30, and (F) 180 min. Scale bar, 10 nm, applies to (C) to (F).

  • Fig. 3 Structural and compositional analyses of Pt octahedral nanocages.

    (A) TEM image of a typical sample. (B) HAADF-STEM image of an individual nanocage. The red circle marks a hole responsible for the dissolution of Pd from the core. (C) High-resolution HAADF-STEM image taken from the region boxed in (B), showing a wall thickness of seven atomic layers. (D) EDS mapping of Pt and Pd. Scale bar, 10 nm.

  • Fig. 4 Electrocatalytic properties of Pt nanocages relative to a commercial Pt/C catalyst.

    (A) Mass and (B) specific activities of the catalysts at 0.9 VRHE. (C) Mass activities (at 0.9 VRHE) and (D) specific ECSAs of the catalysts before and after accelerated durability test. The color scheme applies to all panels.

Supplementary Materials

  • Platinum-based nanocages with subnanometer-thick walls and well-defined, controllable facets

    Lei Zhang, Luke T. Roling, Xue Wang, Madeline Vara, Miaofang Chi, Jingyue Liu, Sang-Il Choi, Jinho Park, Jeffrey A. Herron, Zhaoxiong Xie, Manos Mavrikakis, Younan Xia

    Materials/Methods, Supplementary Text, Tables, Figures, and/or References

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    • Materials and Methods
    • Figs. S1 to S8
    • Tables S1 to S3
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