title: Solution Structures of Highly Active Molecular Ir Water-Oxidation Catalysts from Density Functional Theory Combined with High-Energy X-ray Scattering and EXAFS Spectroscopy.
abstract: The solution structures of highly active Ir water-oxidation catalysts are elucidated by combining density functional theory, high-energy X-ray scattering (HEXS), and extended X-ray absorption fine structure (EXAFS) spectroscopy. We find that the catalysts are Ir dimers with mono-μ-O cores and terminal anionic ligands, generated in situ through partial oxidation of a common catalyst precursor. The proposed structures are supported by (1)H and (17)O NMR, EPR, resonance Raman and UV-vis spectra, electrophoresis, etc. Our findings are particularly valuable to understand the mechanism of water oxidation by highly reactive Ir catalysts. Importantly, our DFT-EXAFS-HEXS methodology provides a new in situ technique for characterization of active species in catalytic systems.
authors.affiliation: Yale Energy Sciences Institute and Department of Chemistry, Yale University , New Haven, Connecticut 06520-8107, United States.
authors.forename: Ke R
authors.initials: KR
authors.lastname: Yang
authors.affiliation: Yale Energy Sciences Institute and Department of Chemistry, Yale University , New Haven, Connecticut 06520-8107, United States.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Matula
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Gihan
authors.initials: G
authors.lastname: Kwon
authors.affiliation: Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
authors.forename: Jiyun
authors.initials: J
authors.lastname: Hong
authors.affiliation: Yale Energy Sciences Institute and Department of Chemistry, Yale University , New Haven, Connecticut 06520-8107, United States.
authors.forename: Stafford W
authors.initials: SW
authors.lastname: Sheehan
authors.affiliation: Yale Energy Sciences Institute and Department of Chemistry, Yale University , New Haven, Connecticut 06520-8107, United States.
authors.forename: Julianne M
authors.initials: JM
authors.lastname: Thomsen
authors.affiliation: Yale Energy Sciences Institute and Department of Chemistry, Yale University , New Haven, Connecticut 06520-8107, United States.
authors.forename: Gary W
authors.initials: GW
authors.lastname: Brudvig
authors.affiliation: Yale Energy Sciences Institute and Department of Chemistry, Yale University , New Haven, Connecticut 06520-8107, United States.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Crabtree
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: David M
authors.initials: DM
authors.lastname: Tiede
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.|Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
authors.forename: Lin X
authors.initials: LX
authors.lastname: Chen
authors.affiliation: Yale Energy Sciences Institute and Department of Chemistry, Yale University , New Haven, Connecticut 06520-8107, United States.
authors.forename: Victor S
authors.initials: VS
authors.lastname: Batista