Ultrathin PtPd-Based Nanorings with Abundant Step Atoms Enhance Oxygen Catalysis

Yingjun Sun; Xu Zhang; Mingchuan Luo; Xu Chen; Lei Wang; Yingjie Li; Mingqiang Li; Yingnan Qin; Chunji Li; Nuoyan Xu; Gang Lu; Peng Gao; Shaojun Guo

doi:10.1002/adma.201802136

Ultrathin PtPd-Based Nanorings with Abundant Step Atoms Enhance Oxygen Catalysis

Adv Mater. 2018 Sep;30(38):e1802136. doi: 10.1002/adma.201802136. Epub 2018 Aug 6.

Authors

Yingjun Sun^{1

2}, Xu Zhang³, Mingchuan Luo¹, Xu Chen⁴, Lei Wang², Yingjie Li¹, Mingqiang Li⁵, Yingnan Qin^{1

2}, Chunji Li¹, Nuoyan Xu¹, Gang Lu³, Peng Gao^{5

6}, Shaojun Guo^{1

7

8

9}

Affiliations

¹ Department of Materials Science & Engineering, College of Engineering, Peking University, Beijing, 100871, China.
² College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
³ Department of Physics and Astronomy, California State University, Northridge, CA, 91330, USA.
⁴ State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
⁵ Electron Microscopy Laboratory, and International Center for Quantum Materials, School of Physics, Peking University, Beijing, 100871, China.
⁶ Collaborative Innovation Centre of Quantum Matter, Beijing, 100871, China.
⁷ BIC-ESAT, College of Engineering, Peking University, Beijing, 100871, China.
⁸ Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing, 100871, China.
⁹ Beijing Key Laboratory for Magnetoeletric Materials and Devices (BKL-MEMD), Peking University, Beijing, 100871, China.

PMID: 30080292
DOI: 10.1002/adma.201802136

Abstract

The lack of highly active and stable catalysts with low Pt usage for the oxygen reduction reaction (ORR) is a major barrier in realizing fuel cell-driven transportation applications. A general colloidal chemistry method is demonstrated for making a series of ultrathin PtPdM (M = Co, Ni, Fe) nanorings (NRs) for greatly boosting ORR catalysis. Different from the traditional ultrathin nanosheets, the ultrathin PtPdM NRs herein have a high portion of step atoms on the edge, high Pt utilization efficiency, and strong ligand effect from M to Pt and fast mass transport of reactants to the NRs. These key features make them exhibit greatly enhanced electrocatalytic activity for the ORR and the oxygen evolution reaction (OER). Among all the PtPdM NRs, the PtPdCo shows the highest ORR mass and specific activities of 3.58 A mg^-1 and 4.90 mA cm^-2 at 0.9 V versus reversible hydrogen electrode (RHE), 23.9 and 24.5-fold larger than those of commercial Pt/C in alkaline electrolyte, respectively. The theoretical calculations reveal that the oxygen adsorption energy (E _O ) can be optimized under the presence of step atoms exposed on the edge and ligand effect induced by Co. They are stable under ORR conditions with negligible changes after 30 000 cycles.

Keywords: fuel cells; multimetallic; nanorings; oxygen reduction; step atoms.

Abstract

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