Oxygen Evolution Reaction Electrocatalysis on Transition Metal Oxides and (Oxy)hydroxides: Activity Trends and Design Principles

Abstract

Poor oxygen evolution reaction (OER) catalysis limits the efficiency of H2 production from water electrolysis and photoelectrolysis routes to large-scale energy storage. Despite nearly a century of research, the factors governing the activity of OER catalysts are not well understood. In this Perspective, we discuss recent advances in understanding the OER in alkaline media for earth-abundant, first-row, transition-metal oxides and (oxy)­hydroxides. We argue that the most-relevant structures for study are thermodynamically stable (oxy)­hydroxides and not crystalline oxides. We discuss thin-film electrochemical microbalance techniques to accurately quantify intrinsic activity and in situ conductivity measurements to identify materials limited by electronic transport. We highlight the dramatic effect that Fe cationsadded either intentionally or unintentionally from ubiquitous electrolyte impuritieshave on the activity of common OER catalysts. We find new activity trends across the first-row transition metals, opposite of the established ones, and propose a new view of OER on mixed-metal (oxy)­hydroxides that illustrates possible design principles and applications.

An Operando Investigation of (Ni–Fe–Co–Ce)Ox System as Highly Efficient Electrocatalyst for Oxygen Evolution Reaction

“…when placed under operating potential, has confounded identification of activity trends of the transition metals, and of identification of the catalytically active metal centers. [34][35][36] We recently reported a high throughput investigation of the (Ni-Fe-Co-Ce)Ox composition space which identified a new, unpredicted Ce-rich composition region of active OER electrocatalysts. 37 Given the comparatively low activity of CeOx, the high catalytic activity of the Ce-rich catalyst is quite surprising, motivating detailed study of this catalyst.…”

Hierarchical Hollow Nanoprisms Based on Ultrathin Ni‐Fe Layered Double Hydroxide Nanosheets with Enhanced Electrocatalytic Activity towards Oxygen Evolution

“…[7,8] Many research efforts have been devoted to developing cost-effective electrocatalysts to replace the state-of-the-art precious-metal-based catalysts. [9][10][11][12][13][14][15][16][17][18][19] Among various promising alternatives,oxides/hydroxides containing first-row transition metals (e.g., Mn, Fe,C o, and Ni)h ave attracted tremendous interest owing to their earth abundance and remarkable OER performance. [12][13][14][15][16][17][18][19] In particular,N i-Fel ayered double hydroxides (LDHs) have been reported as apromising class of most effective OER catalysts in alkaline environments (pH [13][14].…”

“…[9][10][11][12][13][14][15][16][17][18][19] Among various promising alternatives,oxides/hydroxides containing first-row transition metals (e.g., Mn, Fe,C o, and Ni)h ave attracted tremendous interest owing to their earth abundance and remarkable OER performance. [12][13][14][15][16][17][18][19] In particular,N i-Fel ayered double hydroxides (LDHs) have been reported as apromising class of most effective OER catalysts in alkaline environments (pH [13][14]. [20][21][22][23][24][25][26][27] Although thorough investigations are still needed to identify the active sites,t he synergistic interactions between Ni and Fe can indeed dramatically enhance the catalytic activity compared with the individual Ni and Fe components.…”

Liquid Exfoliated Co(OH)2 Nanosheets as Low‐Cost, Yet High‐Performance, Catalysts for the Oxygen Evolution Reaction

“…While the bulk of OER data in the literature corresponds to room temperature (generally between 20-25C) [59] , we believe a temperature study is useful because, industrial alkaline electrolysers operate at elevated temperatures of at least 80C. [60] With this in mind we varied the temperature (electrolyte concentration 5 M NaOH), as shown in figure 4I from 20-50C and observed a 60 mV decrease in overpotentials required to achieve current densities of 50 and 100 mA cm -2 , reaching a global low of 236 mV and 268 mV respectively (iR corrected). This drop in overpotential at a fixed current with increasing temperature is consistent with the work of Miles and co-workers.…”