Activity-Stability Volcano in Supported Electrocatalysis: Single Entity Correlation of Au25 Nanoclusters Between Oxygen Reduction Activity and Metal-Support Interaction.

Metal-support interactions (MSIs) in supported nanoclusters (NCs) represent a crucial factor in the design of highly efficient heterogeneous catalysts, yet the understanding of these MSIs with their catalytic activities in nature remains elusive. Here, we employ single entity collision electrochemistry to reveal an activity-stability volcano relationship in Au25 NCs for oxygen reduction reaction (ORR) at the single entity level. By in situ identification of current amplitude and duration of individual collision events, we directly correlate MSI strength with ORR activity of single Au25 NCs on five representative supports (C, CeO2, SnO2, TiO2, and Co3O4). Our combined experimental findings and theoretical calculations demonstrate that an intermediate MSI strength provided by SnO2 enables favorable charge transfer without overstabilizing intermediates, thereby affording superior ORR activity of Au25 NCs while preserving adequate anchoring. This study introduces a novel methodological framework for probing MSIs at the single entity level, advancing understanding of metal-support interplay in heterogeneous electrocatalysis.