Journal article
Elucidating the formation and structural evolution of platinum single-site catalysts for the hydrogen evolution reaction
- Abstract:
- Platinum single-site catalysts (SSCs) are a promising technology for the production of hydrogen from clean energy sources. They have high activity and maximal platinum-atom utilization. However, the bonding environment of platinum during operation is poorly understood. In this work, we present a mechanistic study of platinum SSCs using operando, synchrotron-X-ray absorption spectroscopy. We synthesize an atomically dispersed platinum complex with aniline and chloride ligands onto graphene and characterize it with ex-situ electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, X-ray absorption near-edge structure spectroscopy (XANES), and extended X-ray absorption fine structure spectroscopy (EXAFS). Then, by operando EXAFS and XANES, we show that as a negatively biased potential is applied, the Pt-N bonds break first followed by the Pt-Cl bonds. The platinum is reduced from platinum(II) to metallic platinum(0) by the onset of the hydrogen-evolution reaction at 0 V. Furthermore, we observe an increase in Pt-Pt bonding, indicating the formation of platinum agglomerates. Together, these results indicate that while aniline is used to prepare platinum SSCs, the single-site complexes are decomposed and platinum agglomerates at operating potentials. This work is an important contribution to the understanding of the evolution of bonding environment in SSCs and provides some molecular insights into how platinum agglomeration causes the deactivation of SSCs over time.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 1.9MB, Terms of use)
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(Preview, Supplementary materials, pdf, 5.1MB, Terms of use)
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- Publisher copy:
- 10.1021/acscatal.1c05958
Authors
- Publisher:
- American Chemical Society
- Journal:
- ACS Catalysis More from this journal
- Volume:
- 12
- Issue:
- 5
- Pages:
- 3173-3180
- Publication date:
- 2022-03-04
- Acceptance date:
- 2022-02-04
- DOI:
- EISSN:
-
2155-5435
- Language:
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English
- Keywords:
- Pubs id:
-
1246381
- Local pid:
-
pubs:1246381
- Deposit date:
-
2022-05-13
- ARK identifier:
Terms of use
- Copyright holder:
- American Chemical Society
- Copyright date:
- 2022
- Rights statement:
- ©2022 American Chemical Society. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
- Licence:
- CC Attribution (CC BY)
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