The Interaction of Water with Free Mn4 O4 (+) Clusters: Deprotonation and Adsorption-Induced Structural Transformations.
As the biological activation and oxidation of water takes place at an inorganic cluster of the stoichiometry CaMn4 O5 , manganese oxide is one of the materials of choice in the quest for versatile, earth-abundant water splitting catalysts. To probe basic concepts and aid the design of artificial water-splitting molecular catalysts, a hierarchical modeling strategy was employed that explores clusters of increasing complexity, starting from the tetramanganese oxide cluster Mn4 O4 (+) as a molecular model system for catalyzed water activation. First-principles calculations in conjunction with IR spectroscopy provide fundamental insight into the interaction of water with Mn4 O4 (+) , one water molecule at a time. All of the investigated complexes Mn4 O4 (H2 O)n (+) (n=1-7) contain deprotonated water with a maximum of four dissociatively bound water molecules, and they exhibit structural fluxionality upon water adsorption, inducing dimensional and structural transformations of the cluster core.
Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm (Germany). sandra.lang@uni-ulm.de.
Sandra M
SM
Lang
Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm (Germany).
Thorsten M
TM
Bernhardt
Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen (The Netherlands).|Anton Pannekoek Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (The Netherlands).
Denis M
DM
Kiawi
Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen (The Netherlands). j.bakker@science.ru.nl.
Joost M
JM
Bakker
School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States).
Robert N
RN
Barnett
School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States). uzi.landman@physics.gatech.edu.
Uzi
U
Landman
ab initio calculations; manganese oxide; oxygen evolving complex; vibrational spectroscopy; water splitting