Two-Dimensional OER Catalysts: Is There a Win-Win Solution for Their Activity and Stability?

Since the oxygen evolution reaction (OER) is the critical half reaction for highly efficient water splitting, OER catalysts with synergistically enhanced activity and stability are now under vigorous development. Two dimensional (2D) OER catalysts possess unique structural characteristics with tunable surface chemistry and electronic properties and thus have received extensive investigation. High activity and high stability of the catalysts are often incompatible because the highly active catalytic species on the 2D framework tend to degrade or reconstruct under the OER operating conditions, which is unfavorable for the long-term stability. In this review, we emphasize the relationship between activity and stability from the perspective of the mechanisms of the OER, the current progress, and the challenges over the widely explored 2D OER catalysts. We will analyze the reconstruction and degradation processes of these catalysts and outline rational strategies to synergistically enhance their activity and stability.