Vertical Nanoconfinement Suppresses Lateral Diffusion for Super-Resolved Spatiotemporal Mapping of Nanocatalytic Dynamics

Abstract Mapping catalytic activity at the single-nanoparticle level is critical for the rational design of high-performance materials. However, current optical techniques are fundamentally limited by molecular diffusion blur. This physical decoupling of the luminescent signal from the catalytic site creates a “spatial information gap” that post-processing alone cannot reconcile. Here, we report a super-resolved imaging platform that overcomes this limitation by utilizing the nanoconfinement effect within a Vertically Oriented Silica Mesoporous Film (VSMF). By confining light-emitting species within vertical nanochannels, we effectively suppress lateral diffusion and regulate mass transport. While bare Pt sites suffer over 70% signal collapse within 20 seconds due to rapid reactant depletion, the VSMF-encapsulated sites maintain a quasi-steady-state flux with only ∼20% decay. When integrated with Super-Resolution Radial Fluctuation (SRRF) algorithms, this platform achieves a spatial resolution significantly below the diffraction limit. This approach revealed that the ECL reaction flux redistributes from the core to the boundary of Pt aggregates as the system transitions from a kinetically controlled to a diffusion-controlled regime. Our work provides a powerful strategy for real-time, super-resolution characterization of nanocatalytic dynamics with extraordinary spatiotemporal accuracy.