Advancing Mn-based electrocatalysts: Evolving from Mn-centered octahedral entities to bulk forms

Developing transition metal compound (TMC) catalysts is complicated by the intricate relationship between their crystal and electronic structures and their catalytic performance. To address this challenge, we propose the “from active unit to catalyst” (FAUC) strategy starting with optimizing the physical property of a Mn-centered [MnO₆] entity to ensure its catalytic performance. These entities are then arranged to reveal how their assembly influences the electronic structures. Notably, a two-dimensional (2D) entity-formed lattice shows a promising low theoretical overpotential (0.08 ​V) for oxygen reduction reaction due to the optimal occupied $d_{z^2}$ orbital position. According to the catalytic requirements of an individual entity and its stacking modes, we further developed a search algorithm to identify three-dimensional (3D) structures from 154,718 candidates, pinpointing CaMnO₃ as the most effective one among the screened candidates. This FAUC approach provides a comprehensive framework for designing catalysts from basic units to complex assemblies.