Metalloenzyme-Inspired Cluster Fabrication within Mesoporous Channels Featuring Optimized Catalytic Microenvironments for Efficient Neutral pH H2O2 Electrosynthesis

In nature, some metalloenzymes facilitate highly efficient catalytic transformations of small molecules, primarily attributed to the effective coupling between their metal cluster active sites and the surrounding microenvironment. Inspired by this, a thermotropic redispersion strategy to incorporate bismuth nanoclusters (Bi NCs) into mesoporous channels, mimicking metalloenzyme-like catalysis to enhance the two-electron oxygen reduction reaction (2e- ORR) for efficient neutral pH H2O2 electrosynthesis, is developed. This model electrocatalyst exhibits exceptional 2e- ORR performance with >95% H2O2 selectivity across 0.2-0.6 V vs RHE in neutral electrolyte. Notably, the system produces up to 7.2 wt% neutral H2O2 solution at an industrially relevant current density of approximate to 320 mA cm-2, with 90% Faradaic efficiency for H2O2 over 120 h in a flow cell, demonstrating significant practical potential. Mechanistic insights reveal that the introduction of Bi NCs enhances the adsorption of the *OOH intermediate, facilitating a highly active 2e- ORR process. Moreover, the mesoporous channels of the carbon support create a favorable catalytic microenvironment for O2 aeration and local alkalinity, further boosting H2O2 productivity. This catalyst design mimics metalloenzymes by optimal integration of the active site with the surrounding microenvironment, offering valuable insights for the rational design of nature-inspired small-molecule catalysts.