Recent Progress in the Development of Screening Methods to Identify Electrode Materials for the Oxygen Evolution Reaction

Abstract

The oxygen evolution reaction (OER) limits the performance of protonexchange membrane electrolyzers since substantial overpotentials of several hundred millivolts are required for the formation of gaseous oxygen at the anode to reach satisfying current densities. Theoreticians trace this to the occurrence of a linear scaling relationship between the OH and OOH adsorbates within the electrocatalytic OER cycle, which thermodynamically restrains this four-electron process. While commonly the breaking of this particular scaling relation is pursued as a promising strategy to enhance catalytic turnover, the present progress report summarizes recent trends in the screening of electrode materials for the OER aside this notion. This contains an extension of thermodynamic-based screening methods by including the kinetics, applied overpotential, and the electrochemical-step symmetry index into the analysis, enabling material screening within a unifying methodology, or material screening by molecular orbital principles and band theories. The combination of activity-based screening methods with a proper assessment of catalyst stability may aid the further search of electrode materials for the OER in the future.

The Sabatier Principle in Electrocatalysis: Basics, Limitations, and Extensions

“…Therefore, this finding has stimulated various studies aiming to find strategies to break scaling relations (Li and Sun, 2016;Pegis et al, 2017;Huang et al, 2019). However, breaking the scaling relationship in itself is not a sufficient condition to realize active materials, because it does not guarantee a lower η TD as the recent literature has shown (Govindarajan et al, 2018;Exner, 2020f;Piqué et al, 2020).…”

“…These authors put forth an alternate activity descriptor, the electrochemical-step symmetry index (ESSI), which in contrast to η TD analyzes the entire free-energy landscape at zero overpotential. As such, the ESSI is a more balanced activity descriptor than η TD and provides better results in the sorting of highly active electrocatalysts (Exner, 2020f;Piqué et al, 2020). Yet, the ESSI does not contain any overpotential effects in its framework.…”

Boosting the Stability of RuO2 in the Acidic Oxygen Evolution Reaction by Tuning Oxygen‐Vacancy Formation Energies: A Viable Approach Beyond Noble‐Metal Catalysts?

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 Material screening in a heuristic fashion is commonly used to identify potential electrode materials for the OER, focusing on the activity by assessing the energetics of the OH, O, and OOH adsorbates. [12] While the conventional approach of linear scaling relationships and thermodynamic volcano analyses was recently extended by including kinetic effects and the applied overpotential into the methodology, [17,18] the assessment of catalyst stability by theoretical methods remains still somewhat complex. [19] The work of Hao et al may open new doors in this field by providing a strategy how OER stability could be assessed in a high-throughput fashion, namely by applying V O as a descriptor for catalyst stability in a class of electrodes and co-doped materials.…”

Comparative Study of Epoxy-CsH2PO4 Composite Electrolytes and Porous Metal Based Electrocatalysts for Solid Acid Electrochemical Cells

“…The electrolyte conductivity has a high impact on the electrochemical performance, (i) reduces the power density of the fuel cell, and (ii) grows the operation voltage on the electrolysis cells [ 18 ]. Therefore, different strategies have been followed to reduce the electrolyte contribution.…”