Transition Metal‐Based Electrocatalysts for Seawater Oxidation

Abstract

Electrocatalytic water splitting is an effective strategy, which can convert intermittent energy such as wind energy and solar energy into renewable and sustainable hydrogen energy. Global freshwater resources are extremely scarce. Compared with freshwater, seawater is a rich and sustainable resource, and it has attracted more and more attention in electrocatalysis. However, the oxygen evolution reaction (OER) is a four‐electron transfer process, which leads to slow reaction kinetics. Moreover, the presence of various elements in seawater and their interference to electrochemistry make the OER in seawater extremely challenging. Herein, the latest progress in the development of transition metal‐based OER electrocatalytic materials for seawater is reviewed by hydroxides, oxides, chalcogenides, phosphides, and nitrides. Focus is made on how to eliminate competitive reaction chlorine evolution reaction of OER in electrolytic seawater. The recent research advances of OER catalyst for selective electrolysis seawater are summarized from the aspects of structure design, mechanism understanding, and performance enhancement strategy. Finally, the challenges, prospects, and research directions of seawater electrocatalysis for OER are introduced.

Nitrogen Plasma Activates CoMn-Layered Double Hydroxides for Superior Electrochemical Oxygen Evolution

“…Recently, transition metal-based compounds have become an ideal choice to replace precious metal catalysts because of their abundant reserves and adjustable structural properties. , For example, oxides, , hydroxides, , layered double hydroxides (LDH), − metal organic frameworks (MOFs), − and their derivatives have attracted lots of research interests. Among them, the LDHs are an important kind of two-dimensional layered anionic clay, which consists of positively charged layers (brucite-like M­(OH) 6 octahedron) and anions between layers. − LDHs possess many advantages, such as the adjustable chemical composition of layers, easy exchange of anions between layers, structural topological transformation, high specific surface area, etc. ,, As catalysts themselves, catalyst carriers, or catalyst precursors, LDHs exhibit many important applications in photocatalysis and electrocatalysis. , In particular, Co–Mn-based double-layer hydroxide has become one of the most active materials in electrolytic water oxidation because of its low cost and easy control of structure .…”

“…14 Recently, transition metal-based compounds have become an ideal choice to replace precious metal catalysts because of their abundant reserves and adjustable structural proper-ties. 15,16 For example, oxides, 17,18 hydroxides, 19,20 layered double hydroxides (LDH), 21−23 metal organic frameworks (MOFs), 24−26 and their derivatives have attracted lots of research interests. Among them, the LDHs are an important kind of two-dimensional layered anionic clay, which consists of positively charged layers (brucite-like M(OH) 6 octahedron) and anions between layers.…”

Amorphous‐Crystalline Interfaces on Hollow Nanocubes Derived from Ir‐Doped Ni–Fe–Zn Prussian Blue Analog Enables High Capability of Alkaline/Acidic/Saline Water Oxidations

“…[ 3,18–23 ] Moreover, these electrocatalysts need to be engineered and modified in order to maintain high selectivity and chloride corrosion resistance during direct seawater splitting in an alkalized saline electrolyte. [ 2,24–25 ]…”

Precise control of the catalyst interface at the atomic level

“…24,25 Fortunately, the activity of a catalyst can be improved by a reasonable strategy for interface-structure design, such as constructing heterojunctions or doping. [26][27][28][29][30] For the first time, Lin et al improved the interfacial activity of Co(OH)F using atomic replacement, which significantly improved the efficiency of oxygen evolution by electrolytic dissolution of water. 31 That work showed that the efficiency of atomic utilization could be high.…”