Revisiting MOF-Derived Single-Atom Electrocatalysts: Limitations, Characterizations, and Design Strategies

Single-atom sites (SASs) and their electrocatalysts offer outstanding catalytic activity and metal efficiency. Metal-organic frameworks (MOFs), with their tunable and multifunctional architectures, serve as ideal precursors for SASs, enabling atomic-level dispersion. However, current research often overlooks critical ambiguities in SAS definitions, intrinsic limitations, and characterization reliability. Moreover, prevalent destructive treatments, such as pyrolysis or sulfidation, inevitably compromise framework integrity, raising concerns regarding the trade-off between structural designability and conductivity. Accordingly, this Mini-Review critically revisits MOF-derived SASs by scrutinizing synthesis limitations and emphasizing the quantitative assessment of atomic utilization efficiency. Representative examples of emerging framework-retaining strategies, including ligand and defect engineering, are discussed to illustrate opportunities for preserving MOF advantages. Finally, future directions are proposed, focusing on dynamic structural reconstruction and operando validation to simultaneously enhance activity, stability, and scalability for practical energy conversion applications.