On the Acid-Base Mechanism for Ruthenium Water Oxidation Catalysts
Author(s)
Wang, Lee-Ping; Wu, Qin; Van Voorhis, Troy
DownloadWangVanVoorhis10a.pdf (2.690Mb)
PUBLISHER_POLICY
Publisher Policy
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Alternative title
Acid-Base Mechanism for Ruthenium Water Oxidation Catalysts
Terms of use
Metadata
Show full item recordAbstract
We present a detailed theoretical study of the pathway for water oxidation in synthetic ruthenium-based catalysts. As a first step, we consider a recently discovered single center catalyst, where experimental observations suggest a purely single-center mechanism. We find low activation energies (<5 kcal/mol) for each rearrangement in the catalytic cycle. In the crucial step of O−O bond formation, a solvent water acts as a Lewis base and attacks a highly oxidized RuV=O. Armed with the structures and energetics of the single-center catalyst, we proceed to consider a representative Ru-dimer which was designed to form O2 via coupling between the two centers. We discover a mechanism that proceeds in analogous fashion to the monomer case, with all the most significant steps occurring at a single catalytic center within the dimer. This acid−base mechanism suggests a new set of strategies for the rational design of multicenter catalysts: rather than coordinating the relative orientations of the subunits, one can focus on coordinating solvation-shell water molecules or tuning redox potentials.
Date issued
2010-04Department
Massachusetts Institute of Technology. Department of ChemistryJournal
Inorganic Chemistry
Publisher
American Chemical Society
Citation
Wang, Lee-Ping, Qin Wu, and Troy Van Voorhis. “Acid−Base Mechanism for Ruthenium Water Oxidation Catalysts.” Inorganic Chemistry 49.10 (2010): 4543–4553.
Version: Author's final manuscript
ISSN
0020-1669
1520-510X