Electrocatalytic H2O Reduction with f-Elements: Mechanistic Insight and Overpotential Tuning in a Series of Lanthanide Complexes

Halter D, Palumbo CT, Ziller JW, Gembicky M, Rheingold AL, Evans WJ, Meyer K (2018)

Publication Type: Journal article

Publication year: 2018

Journal

Journal of the American Chemical Society American Chemical Society

Book Volume: 140

Pages Range: 2587-2594

Journal Issue: 7

DOI: 10.1021/jacs.7b11532

Abstract

Electrocatalytic energy conversion with molecular f-element catalysts is still in an early phase of its development. We here report detailed electrochemical investigations on the recently reported trivalent lanthanide coordination complexes [((Ad,MeArO)3mes)Ln] (1-Ln), with Ln = La, Ce, Pr, Nd, Sm, Gd, Dy, Er, and Yb, which were now found to perform as active electrocatalysts for the reduction of water to dihydrogen. Reactivity studies involving complexes 1-Ln and the Ln(II) analogues [K(2.2.2-crypt)][((Ad,MeArO)3mes)Ln] (2-Ln) suggest a reaction mechanism that differs significantly from the reaction pathway found for the corresponding uranium catalyst [((Ad,MeArO)3mes)U] (1-U). While complexes 1-Ln activate water via a radical pathway, only upon a 1 e- reduction to yield the reduced species 2-Ln, the 5f analogue 1-U directly reduces H2O via a 2 e- pathway. The electrocatalytic H2O reduction by complexes 1-Ln is initiated by the respective Ln(III)/Ln(II) redox couples, which gradually turn to more positive values across the Ln series. This correlation has been exploited to tune the catalytic overpotential of water reduction by choice of the lanthanide ion. Kinetic studies of the 1-Ln series were performed to elucidate correlations between overpotential and turnover frequencies of the 4f-based electrocatalysts.

Authors with CRIS profile

Dominik Halter Lehrstuhl für Anorganische und Allgemeine Chemie Karsten Meyer Lehrstuhl für Anorganische und Allgemeine Chemie

Involved external institutions

University of California Irvine US United States (USA) (US) University of California, San Diego US United States (USA) (US)

How to cite

APA:

Halter, D., Palumbo, C.T., Ziller, J.W., Gembicky, M., Rheingold, A.L., Evans, W.J., & Meyer, K. (2018). Electrocatalytic H2O Reduction with f-Elements: Mechanistic Insight and Overpotential Tuning in a Series of Lanthanide Complexes. Journal of the American Chemical Society, 140(7), 2587-2594. https://dx.doi.org/10.1021/jacs.7b11532

MLA:

Halter, Dominik, et al. "Electrocatalytic H2O Reduction with f-Elements: Mechanistic Insight and Overpotential Tuning in a Series of Lanthanide Complexes." Journal of the American Chemical Society 140.7 (2018): 2587-2594.

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