Recent Advances in the Comprehension and Regulation of Lattice Oxygen Oxidation Mechanism in Oxygen Evolution Reaction

Water electrolysis, a process for producing green hydrogen from renewable energy, plays a crucial role in the transition toward a sustainable energy landscape and the realization of the hydrogen economy. Oxygen evolution reaction (OER) is a critical step in water electrolysis and is often limited by its slow kinetics. Two main mechanisms, namely the adsorbate evolution mechanism (AEM) and lattice oxygen oxidation mechanism (LOM), are commonly considered in the context of OER. However, designing efficient catalysts based on either the AEM or the LOM remains a topic of debate, and there is no consensus on whether activity and stability are directly related to a certain mechanism. Considering the above, we discuss the characteristics, advantages, and disadvantages of AEM and LOM. Additionally, we provide insights on leveraging the LOM to develop highly active and stable OER catalysts in future. For instance, it is essential to accurately differentiate between reversible and irreversible lattice oxygen redox reactions to elucidate the LOM. Furthermore, we discuss strategies for effectively activating lattice oxygen to achieve controllable steady-state exchange between lattice oxygen and an electrolyte (OH⁻ or H₂O). Additionally, we discuss the use of in situ characterization techniques and theoretical calculations as promising avenues for further elucidating the LOM.