Title : Rare-earth promotion for oxygen electrocatalysis
Abstract:
Oxygen electrocatalysis lies in the heart of energy systems such as metal-air battery and water splitting, which are regarded as promising technologies for renewable energy conversion and storage to alleviate the global energy crisis and environmental pollution. However, the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the electrode-electrolyte interface largely limit the whole efficiency of these energy devices, resulting in high energy consumption and poor stability. The commercial catalysts currently used are mainly noble metal-based materials, which possess the high cost and scarce reserve that severely limit their large-scale industrial application, thus necessitating the development of high-performance catalysts with low cost and abundant resources. Transition metal-based catalysts have evolved as a promising alternative due to their low cost, earth abundance, and adjustable electronic properties, while their electrochemical performance (including activity, stability, and selectivity) is still inferior to meet the practical application expectation. Rare-earth species are capable of modulating the intrinsic electronic structure, crystal phase, and surface chemical properties of transition-metal-based catalysts, thereby enhancing their electrocatalytic performance. Yet their complex configuration (such as diverse coordination environments and variable valence states) inhibits the in-depth mechanism investigation of rare-earth promotion effect. Fortunately, using the gradient orbital coupling framework, the rare-earth promotion effect can be well depicted and noted at the atomic and electronic levels, which is able to realize the deep comprehension of rare-earth promotion mechanism in the electrocatalysis area and provide theoretical guidance for the rational design of high-performance rare-earth-modified transition metal-based oxygen electrocatalysts.
