Advances in spinel-type electrocatalysts: Leveraging ligand field theory to elucidate structure-property relationships

Spinels have been widely concerned as a promising class of electrocatalysts due to their appealing catalytic properties and the tunability of their compositions and structures. Ligand field theory (LFT), which describes the origins and the consequences of metal-ligand interactions, offers crucial insights for the design of spinel-type electrocatalysts. In this review, we timely summarize the research progress of spinel electrocatalysts that leverage LFT for structure-property insights, providing a pioneering perspective in this field. This review explores how LFT plays a pivotal role in optimizing the electrocatalytic properties of spinels. It covers important aspects such as identifying the origin of the catalytic properties, tuning the number of active sites, manipulating the e g -filling and the spin state of metal cations, and modulating the 2p band of ligands. We anticipate that this review will provide valuable theoretical guidance and inspire creative spinel designs that excel in electrocatalytic applications. • Research progress on spinel electrocatalysts using ligand field theory (LFT) for structure-property insights was reviewed. • How LFT serves as a guiding principle for the design and optimization of spinel electrocatalysts was explored. • Great compositional and structural tunability of spinel electrocatalysts was emphasized. • Rational design strategies of spinels and their applications as high-performance electrocatalysts are discussed.