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Title: The roles of chalcogenides in O 2 protection of H 2 ase active sites
At some point, all HER (Hydrogen Evolution Reaction) catalysts, important in sustainable H 2 O splitting technology, will encounter O 2 and O 2 -damage. The [NiFeSe]-H 2 ases and some of the [NiFeS]–H 2 ases, biocatalysts for reversible H 2 production from protons and electrons, are exemplars of oxygen tolerant HER catalysts in nature. In the hydrogenase active sites oxygen damage may be extensive (irreversible) as it is for the [FeFe]–H 2 ase or moderate (reversible) for the [NiFe]–H 2 ases. The affinity of oxygen for sulfur, in [NiFeS]–H 2 ase, and selenium, in [NiFeSe]–H 2 ase, yielding oxygenated chalcogens results in maintenance of the core NiFe unit, and myriad observable but inactive states, which can be reductively repaired. In contrast, the [FeFe]–H 2 ase active site has less possibilities for chalcogen-oxygen uptake and a greater chance for O 2 -attack on iron. Exposure to O 2 typically leads to irreversible damage. Despite the evidence of S/Se-oxygenation in the active sites of hydrogenases, there are limited reported synthetic models. This perspective will give an overview of the studies of O 2 reactions with the hydrogenases and biomimetics with focus on our recent studies that compare sulfur and selenium containing synthetic analogues of the [NiFe]–H 2 ase active sites.  more » « less
Award ID(s):
1665258
PAR ID:
10199349
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Chemical Science
Volume:
11
Issue:
35
ISSN:
2041-6520
Page Range / eLocation ID:
9366 to 9377
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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