t 2 Occupancy as an Effective and Predictive Descriptor for the Design of High‐Performance Spinel Oxide Peroxidase‐like Nanozymes

Abstract Nanozymes are next generation of enzyme mimics. Due to the lack of activity descriptors, most nanozymes were discovered through trial‐and‐error strategies or by accident. While e g occupancy in an octahedral crystal field was proven as an effective descriptor, the t 2 in a tetrahedral crystal field has rarely been explored. Here, we first identified t 2 occupancy as an effective and predictive descriptor. Then, we predicted and demonstrated that spinel oxide nanozymes (AB 2 O 4 ) with a t 2 occupancy of around 4.4 at A site had the highest activity. Furthermore, we introduced O β content as a secondary descriptor. The dual descriptor strategy resulted in a three‐dimensional volcanic curve, converging at a vertex. To surpass the limitations of volcanic curves, a dual site optimizing strategy was proposed, guiding the optimization of both A and B sites as Cu and Co, respectively. The designed CuCo 2 O 4 exhibited the highest activity, achieving around 100‐ and 2‐fold enhancement compared to initial material and the state‐of‐the‐art spinel oxide nanozyme LiCo 2 O 4 , respectively. Density functional theory calculations provided a theoretical basis for the catalytic process. This work provides a new strategy for the rational design of nanozymes, and t 2 occupancy may also be applicable to the design of other catalysts.