Reorganization Energies for Interfacial Proton-Coupled Electron Transfer to a Water Oxidation Catalyst
Matthew C. Kessinger, Alexander V. Soudackov, Jenny Schneider, Rachel E. Bangle, Sharon Hammes‐Schiffer, Gerald J. Meyer
Abstract
and the larger reorganization energy for an unwanted competing PCET reaction from the ITO to the oxidized catalyst showcases a significant kinetic advantage for driving solar water oxidation at high pH. Computational analysis revealed a larger inner-sphere reorganization energy contribution for PCET than for ET arising from a more significant change in the Ru-O bond length for the PCET reaction. Extending the Marcus-Gerischer theory to PCET by including the excited electron-proton vibronic states and the proton donor-acceptor motion provided an apparent reorganization energy of 1.01 eV. This study demonstrates that the Marcus-Gerischer theory initially developed for ET can be reliably extended to PCET for quantifying and interpreting reorganization energies observed experimentally.