Final published version
Licence: CC BY: Creative Commons Attribution 4.0 International License
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Elucidating the Influence of Intercalated Anions in NiFe LDH on the Electrocatalytic Behavior of OER
T2 - A Kinetic Study
AU - Berger, Maike
AU - Popa, Ioana M.
AU - Negahdar, Leila
AU - Palkovits, Stefan
AU - Kaufmann, Bastian
AU - Pilaski, Moritz
AU - Hoster, Harry
AU - Palkovits, Regina
PY - 2023/9/14
Y1 - 2023/9/14
N2 - The oxygen evolution reaction (OER) as one half‐cell reaction of electrochemical water splitting has a fundamental impact on water splitting efficiency and thus on the competitiveness of electrochemically generated hydrogen in the energy market. Nickel‐iron layered double hydroxides (NiFe LDH) are among the most promising electrocatalysts for efficient OER under alkaline conditions. Despite intensive research, correlations of the material properties and the resulting kinetically limiting surface processes are poorly investigated. This work focuses on the kinetic behavior of NiFe LDH catalysts containing different anions in the basal spacing in alkaline OER. Steady‐state Tafel plots, impedance measurements as well as reaction order plots were used to elucidate differences in the catalytic performance. All catalysts showed a dual Tafel behavior and fractional reaction orders. For kinetic modelling, the physisorbed hydrogen peroxide mechanism and Temkin adsorption model were adopted to fit experimental data. Our study showed that the intercalated anions affect the kinetics of rate determining steps. The hypophosphite intercalated LDH possessed the highest OER activity and the first step as rate determining. While for both carbonate and borate intercalated NiFe LDH, the second step proved to be rate determining in the low Tafel region, while the first step was found to be rate‐limiting in the high Tafel region.
AB - The oxygen evolution reaction (OER) as one half‐cell reaction of electrochemical water splitting has a fundamental impact on water splitting efficiency and thus on the competitiveness of electrochemically generated hydrogen in the energy market. Nickel‐iron layered double hydroxides (NiFe LDH) are among the most promising electrocatalysts for efficient OER under alkaline conditions. Despite intensive research, correlations of the material properties and the resulting kinetically limiting surface processes are poorly investigated. This work focuses on the kinetic behavior of NiFe LDH catalysts containing different anions in the basal spacing in alkaline OER. Steady‐state Tafel plots, impedance measurements as well as reaction order plots were used to elucidate differences in the catalytic performance. All catalysts showed a dual Tafel behavior and fractional reaction orders. For kinetic modelling, the physisorbed hydrogen peroxide mechanism and Temkin adsorption model were adopted to fit experimental data. Our study showed that the intercalated anions affect the kinetics of rate determining steps. The hypophosphite intercalated LDH possessed the highest OER activity and the first step as rate determining. While for both carbonate and borate intercalated NiFe LDH, the second step proved to be rate determining in the low Tafel region, while the first step was found to be rate‐limiting in the high Tafel region.
KW - electrokinetic study
KW - oxygen evolution reaction
KW - nickel-iron layered double hydroxides
KW - impedance spectroscopy
KW - anionic exchange
U2 - 10.1002/celc.202300235
DO - 10.1002/celc.202300235
M3 - Journal article
VL - 10
JO - ChemElectroChem
JF - ChemElectroChem
SN - 2196-0216
IS - 18
M1 - e202300235
ER -