Universality in Oxygen Evolution Electrocatalysis: High‐Throughput Screening and a Priori Determination of the Rate‐Determining Reaction Step

Abstract

Material screening is commonly based on the assessment of linear scaling relations that translate to a Volcano curve in order to identify promising electrode materials, situated at the apex of the Volcano. Recently, an advanced material‐screening approach, entitled ESSI‐descriptor activity maps, has been introduced by the author. This methodology goes beyond the thermodynamic framework of Volcano plots, as the concept of ESSI‐descriptor activity maps evaluates, besides binding energies, the kinetics, applied overpotential, and catalytic symmetry in terms of the electrochemical‐step symmetry index (ESSI). Herein, the concept of ESSI‐descriptor activity maps is exerted to the oxygen evolution reaction (OER) to derive universal relationships. In contrast to the common procedure in the literature, a suitable range of values for the linear scaling relation's offset is a priori included in the presented model, which enables high‐throughput screening of OER catalysts and determination of the rate‐determining reaction step (rds) at overpotentials corresponding to typical reaction conditions (ηOER=0.40 V).

Dopants fixation of Ruthenium for boosting acidic oxygen evolution stability and activity

“…Besides that, Δ G 2 for formation of OH* has always acted as a descriptor for indicating the activity trends of the modeled materials 38 . The scaling relation of Δ G 2 and Δ G 3 for formation of OH* and OOH* should be also coupled: 2.6 eV ≤ Δ G 2 + Δ G 3 ≤ 3.6 eV 39 . As seen from the relationship of overpotential and Δ G 2 , the calculated Δ G 2 for W 0.2 Er 0.1 Ru 0.7 O 2− δ −1 (1.01 eV) was the apex of the volcano (Supplementary Fig.…”

Overpotential‐Dependent Volcano Plots to Assess Activity Trends in the Competing Chlorine and Oxygen Evolution Reactions

“…Hitherto, this selectivity problem was studied by ΔE O as descriptor in junction with conventional volcano analyses. [28][29][30][31] This finding motivates to re-investigate the CER vs. OER selectivity, applying ΔG OÀ OH as descriptor, with advanced material-screening frameworks, such as overpotential-dependent volcano plots, kinetic scaling relations, or activity maps based on the electrochemical-step symmetry index; [45][46][47]70,71,80] these concepts have been recently introduced by the author and have shown to provide better results in thorough sorting of electrode materials compared to the conventionally applied volcano scheme. [48,74] Table 3.…”

Does a Thermoneutral Electrocatalyst Correspond to the Apex of a Volcano Plot for a Simple Two‐Electron Process?

“…Most of these works refer to amodel system, whereas it is unclear if the findings obtained hold true in ah omologous series of materials on which the screening of electrodes is based. Even if first steps toward ac onsideration of overpotential and kinetics into trend studies within ac lass of materials have been made, [21,[23][24][25][26][54][55][56][57][58] further investigations are necessary to validate the relationship between optimum binding energy and the volcanosapex (Figure 3) for avariety of two-electron and multielectron processes.A so utlined in the present Viewpoint, two different interpretations of the volcanos apex are possible;either 1) optimum performance is ascribed to athermoneutral catalyst at zero overpotential, DG RI = 0V at h = 0V -this precondition is used in the majority of the literature studies-or,2 )optimum performance is given by at hermoneutral catalyst at target overpotential, DG RI = 0V at h > 0V .O bviously,t hermoneutral bonding of RIs,a s approximately observed in nature, [35] is akey factor to design highly active electrocatalysts.Ipersonally conceive that the requirement of at hermoneutral electrocatalyst should be fulfilled at overpotentials corresponding to typical reaction conditions rather than at h = 0V (Figure 3), as substantiated by the discussion of free-energy diagrams and Tafel plots in conjunction with microkinetic modeling described herein.…”