TY - JOUR
T1 - Tracking Minority Species in Redox Reactions
T2 - A Quantitative Combined XAS and Modulation Excitation Study
AU - Ibraliu, Armando
AU - Fan, Xiaolei
AU - Keenan, Luke
AU - Kokumai, Tathiana M.
AU - Aramini, Matteo
AU - Celorrio, Veronica
AU - Greer, Adam J.
AU - Bowron, Daniel T.
AU - Hardacre, Christopher
AU - Diaz-Moreno, Sofia
N1 - Publisher Copyright:
© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.
PY - 2024/11/18
Y1 - 2024/11/18
N2 - Understanding the nature of intermediates/active species in reactions is a major challenge in chemistry. This is because spectator species typically dominate the experimentally derived data and consequently active phase contributions are masked. Transient methods offer a means to bypass this difficulty. In particular, modulation excitation with phase-sensitive detection (ME-PSD) provides a mechanism to distinguish between spectator and reacting species. Herein, modulation excitation (ME) time-resolved (energy dispersive) X-ray absorption spectroscopy, assisted by phase sensitive detection (PSD) analysis, has been applied to the study of a liquid phase process; in this case the classic ferrocyanide/ferricyanide redox couple. Periodic switches of the electrical potential (anodic/cathodic) enabled the use of the ME approach. Structural changes at fractions as low as 2 % of the total number of electroactive species were detected within the X-ray beam probe volume containing ~30 pmol of Fe(II)/Fe(III).
AB - Understanding the nature of intermediates/active species in reactions is a major challenge in chemistry. This is because spectator species typically dominate the experimentally derived data and consequently active phase contributions are masked. Transient methods offer a means to bypass this difficulty. In particular, modulation excitation with phase-sensitive detection (ME-PSD) provides a mechanism to distinguish between spectator and reacting species. Herein, modulation excitation (ME) time-resolved (energy dispersive) X-ray absorption spectroscopy, assisted by phase sensitive detection (PSD) analysis, has been applied to the study of a liquid phase process; in this case the classic ferrocyanide/ferricyanide redox couple. Periodic switches of the electrical potential (anodic/cathodic) enabled the use of the ME approach. Structural changes at fractions as low as 2 % of the total number of electroactive species were detected within the X-ray beam probe volume containing ~30 pmol of Fe(II)/Fe(III).
KW - electrochemistry
KW - EXAFS
KW - hexacyanoferrate
KW - modulation excitation
KW - X-ray absorption spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85206599972&partnerID=8YFLogxK
U2 - 10.1002/anie.202401888
DO - 10.1002/anie.202401888
M3 - Article
C2 - 39115318
AN - SCOPUS:85206599972
SN - 1433-7851
VL - 63
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 47
M1 - e202401888
ER -