TY - JOUR
T1 - Mechanism of Hydrogen Storage and Structural Transformation in Bimetallic Pd-Pt Nanoparticles
AU - Tayal, Akhil
AU - Seo, Okkyun
AU - Kim, Jaemyung
AU - Kobayashi, Hirokazu
AU - Yamamoto, Tomokazu
AU - Matsumura, Syo
AU - Kitagawa, Hiroshi
AU - Sakata, Osami
N1 - Funding Information:
The authors wish to acknowledge Dr. Wolfgang Caliebe and Dr. Vadim Murzin for their help during the XAFS measurements. This project is partially funded by ACCEL (JPMJAC1501) and the Japan Society for the Promotion of Science (JSPS) KAKENHI Nos. 18K04868 and 20K15083. We thank Andrew Jackson, Ph.D., from Edanz Group ( https://en-author-services.edanz.com/ac ) for editing a draft of this manuscript.
Publisher Copyright:
© 2021 The Authors. Published by American Chemical Society.
PY - 2021/5/26
Y1 - 2021/5/26
N2 - The hydrogen storage capacity of Pd nanoparticles (NPs) decreases as the particles become smaller; however, this reduced capacity is ameliorated by addition of Pt. In the present work, the hydrogen storage mechanism and structural transformations of core (Pd)-shell (Pt) (CS) and solid-solution (SS) NPs during hydrogen absorption and desorption (PHAD) processes are investigated. In situ X-ray absorption spectroscopy measurements were performed to study the evolution of electronic and local structures around Pd and Pt during PHAD. Under ambient conditions, Pd and Pt have distinct local structures. The Pd atomic pairs are more strained in CS NPs than in SS NPs. A similar behavior has been seen in CS NPs after PHAD. The Pd K-edge extended X-ray absorption fine structure data indicate that in CS and SS NPs a substantial fraction of the signal derives from Pd-Pd atomic pairs, indicating that Pd clusters remain present even after PHAD. PHAD causes a rearrangement of the interfacial structure, which becomes homogeneously distributed. The higher coverage of active bimetallic sites results in a higher observed hydrogen storage capacity in the SS phase.
AB - The hydrogen storage capacity of Pd nanoparticles (NPs) decreases as the particles become smaller; however, this reduced capacity is ameliorated by addition of Pt. In the present work, the hydrogen storage mechanism and structural transformations of core (Pd)-shell (Pt) (CS) and solid-solution (SS) NPs during hydrogen absorption and desorption (PHAD) processes are investigated. In situ X-ray absorption spectroscopy measurements were performed to study the evolution of electronic and local structures around Pd and Pt during PHAD. Under ambient conditions, Pd and Pt have distinct local structures. The Pd atomic pairs are more strained in CS NPs than in SS NPs. A similar behavior has been seen in CS NPs after PHAD. The Pd K-edge extended X-ray absorption fine structure data indicate that in CS and SS NPs a substantial fraction of the signal derives from Pd-Pd atomic pairs, indicating that Pd clusters remain present even after PHAD. PHAD causes a rearrangement of the interfacial structure, which becomes homogeneously distributed. The higher coverage of active bimetallic sites results in a higher observed hydrogen storage capacity in the SS phase.
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U2 - 10.1021/acsami.0c22432
DO - 10.1021/acsami.0c22432
M3 - Article
C2 - 33988965
AN - SCOPUS:85106368038
VL - 13
SP - 23502
EP - 23512
JO - ACS applied materials & interfaces
JF - ACS applied materials & interfaces
SN - 1944-8244
IS - 20
ER -