Journal ArticleDOI
Oxidation state changes and electron flow in enzymatic catalysis and electrocatalysis through Wannier-function analysis.
Patrick H.-L. Sit,Federico Zipoli,Federico Zipoli,Jia Chen,Roberto Car,Morrel H. Cohen,Morrel H. Cohen,Annabella Selloni +7 more
TLDR
This paper analyzes two cases, superoxide reductase and a proposed hydrogen-producing model electrocatalyst [FeS(2)]/[FeFe](P), a modification of the active site of the diiron hydrogenase enzymes, and introduces a new, generally useful local method for determining OSs, their changes, and the associated bonding changes and electron flow.Abstract:
In catalysis by metalloenzymes and in electrocatalysis by clusters related in structure and composition to the active components of such enzymes transition-metal atoms can play a central role in the catalyzed redox reactions. Changes to their oxidation states (OSs) are critical for understanding the reactions. The OS is a local property and we introduce a new, generally useful local method for determining OSs, their changes, and the associated bonding changes and electron flow. The method is based on computing optimally localized orbitals (OLOs). With this method, we analyze two cases, superoxide reductase (SOR) and a proposed hydrogen-producing model electrocatalyst [FeS(2)]/[FeFe](P), a modification of the active site of the diiron hydrogenase enzymes. Both utilize an under-coordinated Fe site where a one-electron reduction (for SOR) or a two-electron reduction (for [FeFe](P)) of the substrate occurs. We obtain the oxidation states of the Fe atoms and of their critical ligands, the changes of the bonds to those ligands, and the electron flow during the catalytic cycle, thereby demonstrating that OLOs constitute a powerful interpretive tool for unraveling reaction mechanisms by first-principles computations.read more
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Journal ArticleDOI
Characterization of NiFe oxyhydroxide electrocatalysts by integrated electronic structure calculations and spectroelectrochemistry.
Zachary K. Goldsmith,Aparna Karippara Harshan,James B. Gerken,Márton Vörös,Márton Vörös,Giulia Galli,Giulia Galli,Shannon S. Stahl,Sharon Hammes-Schiffer +8 more
TL;DR: A combination of hybrid periodic density functional theory calculations and spectroelectrochemical experiments elucidate the electronic structure and redox thermodynamics of Ni-only and mixed NiFe oxyhydroxide thin-film electrocatalysts and serve as an important benchmark for computational characterization of mixed-metal oxidation states in heterogeneous catalysts.
Journal ArticleDOI
Oxidation States from Wave Function Analysis
TL;DR: A simple and general scheme to derive from wavefuntion analysis the most appropriate atomic/fragment electron configurations in a molecular system, from which oxidation states can be inferred, is introduced.
Journal ArticleDOI
Ab initio study of the role of oxygen and excess electrons in the degradation of CH3NH3PbI3
Linghai Zhang,Patrick H.-L. Sit +1 more
TL;DR: In this paper, the role of mobile excess electrons and oxygens in the degradation of CH3NH3PbI3 perovskite in air has been investigated.
Journal ArticleDOI
Synthesis, Structure, and Catalytic Applications for ortho- and meta-Carboranyl Based NBN Pincer-Pd Complexes
Min Ying Tsang,Clara Viñas,Francesc Teixidor,José Giner Planas,Nerea Conde,Raul SanMartin,María Teresa Herrero,Esther Domínguez,Agustí Lledós,Pietro Vidossich,Duane Choquesillo-Lazarte +10 more
TL;DR: The X-ray structure determination of all carboranyl pincer complexes shows unambiguously B-H activation of the carborane cages, and the results agree with the Pd-B bonds in all complexes exhibiting strong σ-electron donation.
Journal ArticleDOI
Rigorous definition of oxidation states of ions in solids.
TL;DR: The method is based on wave- function topology and the modern theory of polarization, rather than charge density partitioning or wave-function projection, and, as such, reformulates the concept of oxidation state without assuming real-space charge transfer between atoms.
References
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Journal ArticleDOI
Generalized Gradient Approximation Made Simple
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Inhomogeneous Electron Gas
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