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Evaluating Activity for Hydrogen-Evolving Cobalt and Nickel Complexes at Elevated Pressures of Hydrogen and Carbon Monoxide

McCrory, Charles C. L. and Szymczak, Nathaniel K. and Peters, Jonas C. (2016) Evaluating Activity for Hydrogen-Evolving Cobalt and Nickel Complexes at Elevated Pressures of Hydrogen and Carbon Monoxide. Electrocatalysis, 7 (1). pp. 87-96. ISSN 1868-2529. doi:10.1007/s12678-015-0281-y.

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Molecular cobalt and nickel complexes are among the most promising homogeneous systems for electrocatalytic hydrogen evolution. However, there has been little exploration into the effect of gaseous co-additives such as CO and H_2, which may be present in operating hydrogen-evolving or carbon-dioxide reduction systems, on the performance of these molecular electrocatalysts. In this report, we investigate the electrocatalytic activity of six cobalt and nickel complexes supported by tetraazamacrocyclic or diazadiphosphacyclooctane ligands for the reduction of p-toluenesulfonic acid to hydrogen in acetonitrile under inert atmosphere and in the presence of CO and H_2. We present an elevated-pressure electrochemical apparatus capable of reaching CO and H_2 pressures of ca. 15–520 pounds per square inch (psia) (∼1–35 atm), and we use this apparatus to determine binding constants for CO addition for each catalyst and study the inhibition of the electrocatalysis as a function of CO and H_2 pressure. In the case of CO, the extent of catalytic inhibition is correlated to the binding constant, with the cobalt complexes showing a greater degree of catalyst inhibition compared to the nickel complexes. In the case of H2, no complex showed appreciable electrocatalytic inhibition even at H_2 pressures of ca. 500 psia.

Item Type:Article
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URLURL TypeDescription ReadCube access
McCrory, Charles C. L.0000-0001-9039-7192
Szymczak, Nathaniel K.0000-0002-1296-1445
Peters, Jonas C.0000-0002-6610-4414
Additional Information:© 2015 Springer Science+Business Media New York. First online: 05 October 2015. Financial support for this work was provided by an NSF Center for Chemical Innovation (CHE-0802907). We also thank David C. Lacy and Wesley K. Kramer for many useful discussions.
Funding AgencyGrant Number
Subject Keywords:Electrocatalysis; Hydrogen evolution; Water splitting; Solar fuels
Issue or Number:1
Record Number:CaltechAUTHORS:20151012-110949195
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Official Citation:McCrory, C.C.L., Szymczak, N.K. & Peters, J.C. Electrocatalysis (2016) 7: 87. doi:10.1007/s12678-015-0281-y
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:60975
Deposited By: Tony Diaz
Deposited On:15 Oct 2015 22:51
Last Modified:10 Nov 2021 22:42

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