Atomic Layer-by-Layer Deposition of Platinum on Palladium Octahedra for Enhanced Catalysts toward the Oxygen Reduction Reaction
- Georgia Inst. of Technology, Atlanta, GA (United States). School of Chemistry and Biochemistry
- Georgia Inst. of Technology, Atlanta, GA (United States). Wallace H. Coulter Dept. of Biomedical Engineering
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemical and Biological Engineering
- Univ. of Texas, Dallas, TX (United States). Dept. of Materials Science and Engineering
- Department of Materials Science and Engineering, University of Texas at Dallas
- Georgia Inst. of Technology, Atlanta, GA (United States). School of Chemistry and Biochemistry, Wallace H. Coulter Dept. of Biomedical Engineering
We systematically evaluated two different approaches to the syntheses of Pd@PtnL (n = 2–5) core–shell octahedra. We initially prepared the core–shell octahedra using a polyol-based route by titrating a Pt(IV) precursor into the growth solution containing Pd octahedral seeds at 200 °C through the use of a syringe pump. The number of Pt atomic layers could be precisely controlled from two to five by increasing the volume of the precursor solution while fixing the amount of seeds. We then demonstrated the synthesis of Pd@PtnL octahedra using a water-based route at 95 °C through the one-shot injection of a Pt(II) precursor. Due to the large difference in reaction temperature, the Pd@PtnL octahedra obtained via the water-based route showed sharper corners than their counterparts obtained through the polyol-based route. When compared to a commercial Pt/C catalyst based upon 3.2 nm Pt particles, the Pd@PtnL octahedra prepared using both methods showed similar remarkable enhancement in terms of activity (both specific and mass) and durability toward the oxygen reduction reaction. These calculations based upon periodic, self-consistent density functional theory suggested that the enhancement in specific activity for the Pd@PtnL octahedra could be attributed to the destabilization of OH on their PtnL*/Pd(111) surface relative to the {111} and {100} facets exposed on the surface of Pt/C. Finally. the destabilization of OH facilitates its hydrogenation, which was found to be the rate-limiting step of the oxygen reduction reaction on all these surfaces.
- Research Organization:
- Univ. of Wisconsin, Madison, WI (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Contributing Organization:
- EMSL; CNM at ANL; and NERSC
- Grant/Contract Number:
- FG02-05ER15731; AC02-06CH11357; AC02-05CH11231
- OSTI ID:
- 1396170
- Journal Information:
- ACS Nano, Vol. 9, Issue 3; ISSN 1936-0851
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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