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Mechanistic study of an immobilized molecular electrocatalyst by in situ gap-plasmon-assisted spectro-electrochemistry

Research output: Contribution to journalArticlepeer-review

Demelza Wright, Qianqi Lin, Dénes Berta, Tamás Földes, Andreas Wagner, Jack Griffiths, Charlie Readman, Edina Rosta, Erwin Reisner, Jeremy J. Baumberg

Original languageEnglish
Pages (from-to)157-163
Number of pages7
JournalNature Catalysis
Volume4
Issue number2
DOIs
PublishedFeb 2021

Bibliographical note

Funding Information: We thank G. Di Martino for support with spectro-electrochemical cell design, B. de Nijs for support with Raman facilities and D.-B. Grys for support with understanding of polarized and unpolarized DFT. We acknowledge funding from the EPSRC (nos. EP/ L027151/1 and EP/R013012/1) and Cambridge NanoDTC (no. EP/L015978/1 to D.W. and C.R.), and the ERC (no. 757850 BioNet to D.B. and T.F.). We are grateful to the UK Materials and Molecular Modelling Hub for computational resources, which is partially funded by EPSRC (no. EP/P020194/1). We acknowledge use of the research computing facility (Rosalind) at King’s College London (https://rosalind.kcl.ac.uk). Publisher Copyright: © 2021, The Author(s), under exclusive licence to Springer Nature Limited. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

King's Authors

Abstract

Immobilized first-row transition metal complexes are potential low-cost electrocatalysts for selective CO2 conversion in the production of renewable fuels. Mechanistic understanding of their function is vital for the development of next-generation catalysts, although the poor surface sensitivity of many techniques makes this challenging. Here, a nickel bis(terpyridine) complex is introduced as a CO2 reduction electrocatalyst in a unique electrode geometry, sandwiched by thiol-anchoring moieties between two gold surfaces. Gap-plasmon-assisted surface-enhanced Raman scattering spectroscopy coupled with density functional theory calculations reveals that the nature of the anchoring group plays a pivotal role in the catalytic mechanism. Our in situ spectro-electrochemical measurement enables the detection of as few as eight molecules undergoing redox transformations in individual plasmonic hotspots, together with the calibration of electrical fields via vibrational Stark effects. This advance allows rapid exploration of non-resonant redox reactions at the few-molecule level and provides scope for future mechanistic studies of single molecules. [Figure not available: see fulltext.]

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