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Abstract This article reports a facile method for the synthesis of Pd‐Ru nanocages by activating the galvanic replacement reaction between Pd nanocrystals and a Ru(III) precursor with I‐ions. The as‐synthesized nanocages feature a hollow interior, ultrathin wall of ≈2.5 nm in thickness, and a cubic shape. Our quantitative study suggests that the reduction rate of the Ru(III) precursor can be substantially accelerated upon the introduction of I‐ions and then retarded as the ratio of I‐/Ru3+is increased. The Pd‐Ru nanocages take an alloy structure, with the Ru atoms in the nanocages crystallized in a face‐centered cubic structure instead of the hexagonal close‐packed phase taken by bulk Ru. Using Pd nanocubes with different edge lengths, the dimensions of the nanocages in the range of 6−18 nm can readily be tuned. When tested as catalysts toward the electro‐oxidation of ethylene glycol and glycerol, respectively, the Pd‐Ru cubic nanocages prepared from 18 nm Pd cubes exhibit 5.1‐ and 6.2‐fold enhancements in terms of mass activity relative to the commercial Pd/C. After 1000 cycles of accelerated durability test, the mass activities of the nanocages are still 3.3 and 3.7 times as high as that of the pristine commercial Pd/C catalyst, respectively.
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How to Remove the Capping Agent from Pd Nanocubes without Destructing Their Surface Structure for the Maximization of Catalytic Activity?
Abstract We report a robust method for effectively removing the chemisorbed Br−ions, a capping agent, from the surface of Pd nanocubes to maximize their catalytic activity. The Br−ions can be removed by simply heating the sample in water, but the desorption of Br−ions will expose the underneath Pd atoms to the O2from air for the formation of a relatively thick oxide layer. During potential cycling, the oxide layer evolves into detrimental features such as steps and terraces. By introducing a trace amount of hydrazine into the system, the Br−ions can be removed by heating without forming a thick oxide layer. The as‐cleaned nanocubes show greatly enhanced activity toward formic acid oxidation. This cleaning method can also remove Br−ions from Rh nanocubes and it is expected to work for other combinations of nanocrystals and capping agents.
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- Award ID(s):
- 1804970
- PAR ID:
- 10237066
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 59
- Issue:
- 43
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 19129-19135
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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