Objective evaluation of the activity of electrocatalysts for water oxidation is of fundamental importance for the development of promising energy conversion technologies including integrated solar water-splitting devices, water electrolyzers, and Li-air batteries. However, current methods employed to evaluate oxygen-evolving catalysts are not standardized, making it difficult to compare the activity and stability of these materials. We report a protocol for evaluating the activity, stability, and Faradaic efficiency of electrodeposited oxygen-evolving electrocatalysts. In particular, we focus on methods for determining electrochemically active surface area and measuring electrocatalytic activity and stability under conditions relevant to an integrated solar water-splitting device. Our primary figure of merit is the overpotential required to achieve a current density of 10 mA cm–2 per geometric area, approximately the current density expected for a 10% efficient solar-to-fuels conversion device. Utilizing ...

Benchmarking Heterogeneous Electrocatalysts for the Oxygen Evolution Reaction

https://dspace.library.uu.nl/bitstream/handle/1874/23806/brug_84_the+analysis+of+electrode+impedances.pdf?sequence=1

The analysis of electrode impedances complicated by the presence of a constant phase element

Determination of effective capacitance and film thickness from constant-phase-element parameters

Electrochemical impedance spectroscopy (EIS) is a powerful tool to investigate properties of materials and electrode reactions. This Primer provides a guide to the use of EIS with a comparison to other electrochemical techniques. The analysis of impedance data for reduction of ferricyanide in a KCl supporting electrolyte is used to demonstrate the error structure for impedance measurements, the use of measurement and process models, as well as the sensitivity of impedance to the evolution of electrode properties. This Primer provides guidelines for experimental design, discusses the relevance of accuracy contour plots to wiring and instrumentation selection, and emphasizes the importance of the Kramers-Kronig relations to data validation and analysis. Applications of EIS to battery performance, metal and alloy corrosion, and electrochemical biosensors are highlighted. Electrochemical impedance measurements depend on both the mechanism under investigation and extrinsic parameters, such as the electrode geometry. Experimental complications are discussed, including the influence of nonstationary behaviour at low frequencies and the need for reference electrodes. Finally, emerging trends in experimental and interpretation approaches are also described.

/pdf/electrochemical-impedance-spectroscopy-3e6x9qlxk6.pdf

M. Sluyters-Rehbach

Papers

On the impedance of galvanic cells: XXIV. The impedance of the In3+/In(Hg) electrode reaction in KSCN and KCl solution

On the catalytic effect of thiourea on the electrochemical reduction of cadmium(II) ions at the DME from aqueous 1 M KF solutions

Distribution of the nucleation rate in the vicinity of a growing spherical cluster: Part 1. Theory and simulation results

The influence of reactant adsoption on limiting currents in normal pulse polarography: The ranges of low and high concentrations

Distribution of the nucleation rate in the vicinity of a growing spherical cluster.