Direct evidence of cobalt oxyhydroxide formation on a La_0.2Sr_0.8CoO₃ perovskite water splitting catalyst

Abstract

Understanding the mechanism of oxygen evolution reaction (OER) on perovskite materials is of great interest for the development of more active catalysts. Despite the huge amount of literature reports, the...

Atomistic Insights into Activation and Degradation of La0.6Sr0.4CoO3−δ Electrocatalysts under Oxygen Evolution Conditions

“…The phase transition of the perovskite surface of mixed cobalt valency of nominally (III)/(IV) character toward a Co-oxyhydroxide phase with an oxidation state of Co­(III) is consistent with the EELS results presented above, which have indicated a reduction of the average Co oxidation state of the operated catalyst surface. Furthermore, the observation of CoO­(OH) formation is consistent with recent reports for LSCO OER electrocatalysts . Interestingly, the cobalt oxyhydroxide component was vanished after the end of lifetime, leaving behind a Co 2 p 3/2 and O 1 s signature similar to the initial state, while a clear La­(OH) 3 signature remains visible (cf.…”

“…Furthermore, the observation of CoO(OH) formation is consistent with recent reports for LSCO OER electrocatalysts. 54 Interestingly, the cobalt oxyhydroxide component was vanished after the end of lifetime, leaving behind a Co 2p 3/2 and O 1s signature similar to the initial state, while a clear La(OH) 3 signature remains visible (cf. Figure S9).…”

Water inhibition and role of palladium adatoms on Pd/Al2O3 catalysts during methane oxidation

“…Based on the literature, hydroxyls and adsorbed water should give two distinct peaks (separated by approx. 1.0 eV) [59]. However, because both signals are due to the presence of water and they tend to become undistinguishable at higher temperature, we decided to fit their signals with a single peak.…”

Deeper mechanistic insights into epitaxial nickelate electrocatalysts for the oxygen evolution reaction

“…There has been mounting evidence that shows the surface and the ''bulk'' (at least several nanometers from the interface into the electrocatalysts) can participate in the electrochemical reaction, and often determines the kinetics and performance of these electrocatalysts. 15,[23][24][25][26][27] Therefore, a holistic picture considering the solid/liquid interfaces, as well as the constituent ions and ionic defects of TMOs, becomes important for understanding the reaction mechanism and guiding the predictive design of nickelate OER electrocatalysts. Due to the participation of electrocatalyst ''bulk'' during the electrochemical reactions, a wide range of dynamic mechanisms and phenomena have been observed.…”