Electrocatalytic water oxidation with layered double hydroxides confining single atoms

Abstract

The oxygen evolution reaction (OER) is the bottleneck in water electrolysis towards green hydrogen generation because of its sluggish reaction kinetics. Layered double hydroxides (LDHs) and single-atom catalysts stand out as two of the most effective electrocatalysts, and emerge as two frontier research fields in electrocatalysis. Integration of the two aspects endows a new category of catalysts, which could be an independent research field, possessing the merits of compositional and structural flexibility, tenability nature, and unique electronic structures. For this reason, in this article, we will focus on the concept of layered double hydroxides (LDHs) confining single atoms for OER. First, we state the LDHs structure, fundamentals of OER in LDHs as well as its stepwise mechanism. Second, recent advances in the rational design of LDHs with confined single atoms toward OER are summarized. Specifically, the very recent developed in situ X-ray absorption spectroscopy measurement for unveiling the strong metal–support interaction to stabilize the confined single-atoms during anodic reactions is introduced, serving as a benchmark pathway to exactly identify the active sites during the OER as well as other catalytic behaviors. Finally, the conclusion and future perspectives are stated on the basis of its current development.