Free energy difference to create the M-OH* intermediate of the oxygen evolution reaction by time-resolved optical spectroscopy.
Nat Mater
; 21(1): 88-94, 2022 01.
Article
em En
| MEDLINE
| ID: mdl-34725518
ABSTRACT
Theoretical descriptors differentiate the catalytic activity of materials for the oxygen evolution reaction by the strength of oxygen binding in the reactive intermediate created upon electron transfer. Recently, time-resolved spectroscopy of a photo-electrochemically driven oxygen evolution reaction followed the vibrational and optical spectra of this intermediate, denoted M-OH*. However, these inherently kinetic experiments have not been connected to the relevant thermodynamic quantities. Here we discover that picosecond optical spectra of the Ti-OH* population on lightly doped SrTiO3 are ordered by the surface hydroxylation. A Langmuir isotherm as a function of pH extracts an effective equilibrium constant relatable to the free energy difference of the first oxygen evolution reaction step. Thus, time-resolved spectroscopy of the catalytic surface reveals both kinetic and energetic information of elementary reaction steps, which provides a critical new connection between theory and experiment by which to tailor the pathway of water oxidation and other surface reactions.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Oxigênio
Idioma:
En
Revista:
Nat Mater
Assunto da revista:
CIENCIA
/
QUIMICA
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos