Hydrogen Evolution on Electrode‐Supported Pt n Clusters: Ensemble of Hydride States Governs the Size Dependent Reactivity
[1];
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[4]
- Department of Chemistry and Biochemistry University of California, Los Angeles 607 Charles E. Young Drive 90095-1569 Los Angeles CA USA
- Department of Chemistry, University of Utah 315 South 1400 East 84112 Salt Lake City UT USA
- Department of Chemistry and Biochemistry University of California, Los Angeles 607 Charles E. Young Drive 90095-1569 Los Angeles CA USA, Department of Chemical and Biomolecular Engineering University of California, Los Angeles 5531 Boelter Hall 90095-1569 Los Angeles CA USA, California NanoSystem Institute University of California, Los Angeles 570 Westwood Plaza 90095-1569 Los Angeles CA USA
- Department of Chemistry and Biochemistry University of California, Los Angeles 607 Charles E. Young Drive 90095-1569 Los Angeles CA USA, California NanoSystem Institute University of California, Los Angeles 570 Westwood Plaza 90095-1569 Los Angeles CA USA
Abstract We report the size‐dependent activity and stability of supported Pt 1,4,7,8 for electrocatalytic hydrogen evolution reaction, and show that clusters outperform polycrystalline Pt in activity, with size‐dependent stability. To understand the size effects, we use DFT calculations to study the structural fluxionality under varying potentials. We show that the clusters can reshape under H coverage and populate an ensemble of states with diverse stoichiometry, structure, and thus reactivity. Both experiment and theory suggest that electrocatalytic species are hydridic states of the clusters (≈2 H/Pt). An ensemble‐based kinetic model reproduces the experimental activity trend and reveals the role of metastable states. The stability trend is rationalized by chemical bonding analysis. Our joint study demonstrates the potential‐ and adsorbate‐coverage‐dependent fluxionality of subnano clusters of different sizes and offers a systematic modeling strategy to tackle the complexities.
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- NONE; SC0020125; AC02-05CH11231
- OSTI ID:
- 1983511
- Journal Information:
- Angewandte Chemie, Journal Name: Angewandte Chemie Journal Issue: 20 Vol. 135; ISSN 0044-8249
- Publisher:
- Wiley Blackwell (John Wiley & Sons)Copyright Statement
- Country of Publication:
- Germany
- Language:
- English
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