Electrocatalytic H 2 Generation from Water Relying on Cooperative Ligand Electron Transfer in "PN 3 P" Pincer-Supported Ni II Complexes.

Autor: Norouziyanlakvan S; Department of Chemistry and Biomolecular Sciences, Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie, Ottawa, ON K1 N 6 N5., Rao GK; Department of Chemistry and Biomolecular Sciences, Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie, Ottawa, ON K1 N 6 N5., Ovens J; Department of Chemistry and Biomolecular Sciences, Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie, Ottawa, ON K1 N 6 N5., Gabidullin B; Department of Chemistry and Biomolecular Sciences, Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie, Ottawa, ON K1 N 6 N5., Richeson D; Department of Chemistry and Biomolecular Sciences, Centre for Catalysis Research and Innovation, University of Ottawa, 10 Marie Curie, Ottawa, ON K1 N 6 N5.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2021 Sep 24; Vol. 27 (54), pp. 13518-13522. Date of Electronic Publication: 2021 Aug 20.
DOI: 10.1002/chem.202102031
Abstrakt: Water is the most sustainable source for H 2 production, and the efficient electrocatalytic production of H 2 from mixed water/acetonitrile solutions by using two new air-stable nickel(II) pincer complexes, [Ni(κ 3 -2,6-{Ph 2 PNR} 2 (NC 5 H 3 )Br 2 ] (R=H I, Me II) is reported. Hydrogen generation from H 2 O/CH 3 CN solutions is initiated at -2 V against Fc +/0 , and bulk electrocatalysis studies showed that the catalyst functions with an excellent Faradaic efficiency and a turnover frequency of 160 s -1 . A DFT computational investigation of the reduction behavior of I and II revealed a correlation of H 2 formation with charge donation from electrons originating in a reduced ligand-localized orbital. As a result, these catalysts are proposed to proceed by a novel mechanism involving electron/proton transfer between a Ni 0I species bonded to an anionic PN 3 P ligand ("L - /Ni 0I ") and a Ni I -hydride ("Ni-H"). Furthermore, these catalysts are able to reduce phenol and acetic acid, more active proton sources, at lower potentials that correlate with the substrate pK a .
(© 2021 Wiley-VCH GmbH.)
Databáze: MEDLINE
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