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Electrochemical and spectroscopic methods for evaluating molecular electrocatalysts

Nature Reviews Chemistry volume 1, Article number: 0039 (2017) Cite this article

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Abstract

Modern energy challenges have amplified interest in transition metal-based molecular electrocatalysts for fuel-forming reactions. The activity of these homogeneous electrocatalysts, and the mechanisms by which they operate, can be uncovered using state-of-the-art electrochemical methods. Catalyst performance can be benchmarked according to metrics obtainable from cyclic voltammograms by analysis of catalytic plateau currents and peak potentials, as well as by foot-of-the-wave analysis. The application of complementary spectroscopic techniques, including spectroelectrochemistry, stopped-flow rapid mixing and transient absorption, are also discussed. In this Review, we present case studies highlighting the utility of these analytical methods in the context of renewable energy. Alongside these examples is a discussion of the theoretical underpinnings of each method, outlining the conditions necessary for the analysis to be rigorous and the type of information that can then be extracted.

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Figure 1: Illustration of a three-electrode cell and an idealized example of a cyclic voltammogram.
Figure 2: Kinetic zone diagram describing the expected voltammetric responses for electrocatalysts operating by a EC′ mechanism.
Figure 3: Examples for catalytic plateau current and foot-of-the-wave analyses.
Figure 4: Applications of peak shift analysis in electrocatalysis.
Figure 5: Illustrations of UV–visible and infrared spectroelectrochemical cells.
Figure 6: Experimental setup for and sample data from stopped-flow rapid mixing and transient absorption spectroscopy.

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Acknowledgements

This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under Award DE-SC0015303. J.L.D. acknowledges support from a Packard Fellowship for Science and Engineering and the Alfred P. Sloan Foundation.

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  1. Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina, 27599-3290, USA

    Katherine J. Lee, Noémie Elgrishi, Banu Kandemir & Jillian L. Dempsey

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Lee, K., Elgrishi, N., Kandemir, B. et al. Electrochemical and spectroscopic methods for evaluating molecular electrocatalysts. Nat Rev Chem 1, 0039 (2017). https://doi.org/10.1038/s41570-017-0039

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