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Title: Comment on "New Insights in the Electrocatalytic Proton Reduction and Hydrogen Oxidation by Bioinspired Catalysts. A DFT Investigation"

In the title paper, Vetere et al. reported a computational investigation of the mechanism of H 2 oxidation/proton reduction using a model of nickel-based electrocatalysts that incorporates pendant amines in cyclic phosphorus ligands. These catalysts are attracting considerable attention owing to their high turnover rates and relatively low overpotentials. These authors interpreted the results of their calculations as evidence for a symmetric bond cleavage of H 2 leading directly to two protonated amines in concert with a two-electron reduction of the Ni(II) site to form a Ni(0) diproton state. Proton reduction would involve a reverse symmetric bond formation. We report here an analysis that refutes the interpretation by these authors. We give, for the same model system, the structure of a heterolytic cleavage transition state consistent with the presence of the Ni(II) center acting as a Lewis acid and the pendant amines acting as Lewis bases. We present the associated intrinsic reaction coordinate (IRC) pathway connecting the dihydrogen (η2-H 2 ) adduct and a hydride–proton state. We report also the transition state and associated IRC for the proton rearrangement from a hydride–proton state to a diproton state. Finally, we complete the characterization of the transition state reported by Vetere etmore » al. through a determination of the corresponding IRC. In summary, H 2 oxidation/proton reduction with this class of catalysts involves a heterolytic bond breaking/formation.« less
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  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Publication Date:
OSTI Identifier:
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory; Journal Volume: 115; Journal Issue: 18; Related Information: CME partners with Pacific Northwest National Laboratory (lead); University of Illinois, Urbana-Champaign; Pennsylvania State University; University of Washington; University of Wyoming
American Chemical Society
Research Org:
Energy Frontier Research Centers (EFRC); Center for Molecular Electrocatalysis (CME)
Sponsoring Org:
USDOE SC Office of Basic Energy Sciences (SC-22)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY catalysis (homogeneous); catalysis (heterogeneous); solar (fuels); bio-inspired; energy storage (including batteries and capacitors); hydrogen and fuel cells; charge transport; materials and chemistry by design; synthesis (novel materials)