TY - JOUR
T1 - Atomic PdAu Interlayer Sandwiched into Pd/Pt Core/Shell Nanowires Achieves Superstable Oxygen Reduction Catalysis
AU - Tao, Lu
AU - Huang, Bolong
AU - Jin, Fengdan
AU - Yang, Yong
AU - Luo, Mingchuan
AU - Sun, Mingzi
AU - Liu, Qian
AU - Gao, Faming
AU - Guo, Shaojun
N1 - Funding Information:
This work was financially supported by the Beijing Natural Science Foundation (Nos. JQ18005, Z190010), National Natural Science Foundation of China (NSFC) (21771156, 21875205, and 21671168), National R&D Program of China (2017YFA0206701), the China Postdoctoral Science Foundation (No. 2019M660290), the start-up support from Peking University and Young Thousand Talented Program, and the Early Career Scheme (ECS) fund (Grant No. PolyU 253026/16P) from the Research Grant Council (RGC) in Hong Kong.
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/9/22
Y1 - 2020/9/22
N2 - Rationally designing the core/shell architecture of Pt-based electrocatalysts has been demonstrated as an effective way to induce a surface strain effect for promoting the sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode of fuel cells. However, unstable core dissolution and structural collapse usually occur in Pt-based core/shell catalysts during the long-term cycling operation, greatly impacting actual fuel cell applications. Impeding the dissolution of cores beneath the Pt shells is the key to enhancing the catalytic stability of materials. Herein, a method for sandwiching atomic PdAu interlayers into one-dimensional (1D) Pd/Pt core/shell nanowires (NWs) is developed to greatly boost the catalytic stability of subnanometer Pt shells for ORR. The Pd/PdAu/Pt core/shell/shell NWs display only 7.80% degradation of ORR mass activity over 80 000 potential cycles with no dissolution of Pd cores and good preservation of the holistic sandwich core/shell nanostructures. This is a significant improvement of electrocatalytic stability compared with the Pd/Pt core/shell NWs, which deformed and inactivated over 80 000 potential cycles. The density functional theory (DFT) calculations further demonstrate that the electron-transfer bridge Pd and electron reservoir Au, serving in the PdAu atomic interlayer, both guarantee the preservation of the high electroactivity of surface Pt sites during the long-term ORR stability test. In addition, the Pd/PdAu/Pt NWs show a 1.7-fold higher mass activity (MA) for ORR than the conventional Pd/Pt NWs. The enhanced activity can be attributed to the strong interaction between PdAu interlayers and subnanometer-Pt shells, which suppresses the competitive Pd-4d bands and boosts the surface Pt-5d bands toward the Fermi level for higher electroactivity, proved from DFT.
AB - Rationally designing the core/shell architecture of Pt-based electrocatalysts has been demonstrated as an effective way to induce a surface strain effect for promoting the sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode of fuel cells. However, unstable core dissolution and structural collapse usually occur in Pt-based core/shell catalysts during the long-term cycling operation, greatly impacting actual fuel cell applications. Impeding the dissolution of cores beneath the Pt shells is the key to enhancing the catalytic stability of materials. Herein, a method for sandwiching atomic PdAu interlayers into one-dimensional (1D) Pd/Pt core/shell nanowires (NWs) is developed to greatly boost the catalytic stability of subnanometer Pt shells for ORR. The Pd/PdAu/Pt core/shell/shell NWs display only 7.80% degradation of ORR mass activity over 80 000 potential cycles with no dissolution of Pd cores and good preservation of the holistic sandwich core/shell nanostructures. This is a significant improvement of electrocatalytic stability compared with the Pd/Pt core/shell NWs, which deformed and inactivated over 80 000 potential cycles. The density functional theory (DFT) calculations further demonstrate that the electron-transfer bridge Pd and electron reservoir Au, serving in the PdAu atomic interlayer, both guarantee the preservation of the high electroactivity of surface Pt sites during the long-term ORR stability test. In addition, the Pd/PdAu/Pt NWs show a 1.7-fold higher mass activity (MA) for ORR than the conventional Pd/Pt NWs. The enhanced activity can be attributed to the strong interaction between PdAu interlayers and subnanometer-Pt shells, which suppresses the competitive Pd-4d bands and boosts the surface Pt-5d bands toward the Fermi level for higher electroactivity, proved from DFT.
KW - core/shell nanowires
KW - oxygen reduction reaction
KW - PdAu interlayer
KW - stability
KW - subnanometer Pt catalysts
UR - http://www.scopus.com/inward/record.url?scp=85091566294&partnerID=8YFLogxK
U2 - 10.1021/acsnano.0c04061
DO - 10.1021/acsnano.0c04061
M3 - Journal article
C2 - 32816456
AN - SCOPUS:85091566294
SN - 1936-0851
VL - 14
SP - 11570
EP - 11578
JO - ACS Nano
JF - ACS Nano
IS - 9
ER -