Electrode-Orthogonal Non-Covalent Self-Assembly Programs Microenvironments around Molecular Electrocatalysts

Here, we introduce a catalyst design strategy where non-covalent self-assembly enables molecular control over the active site and microenvironment at the same time to drive efficient electrosynthesis in water. Using anthraquinone-catalyzed H₂O₂ electrosynthesis from O₂ under neutral conditions as a model system, we design anthraquinone-functionalized amphiphiles that self-assemble at polarized electrodes in one in situ step via electrostatic and van der Waals interactions. This process pins and concentrates anthraquinone in a hydrophobic microenvironment that increases the basicity of active intermediates, otherwise poorly accessible in the bulk, by 3 pKa units. The self-assembled catalyst consequently enhances O₂ reduction over the control catalyst that remains in the bulk solution and does not tether to the electrode. As self-assembly is reversible and agnostic to the surface chemistry of the electrode, this strategy can be translated to high-surface-area electrodes, catalyzing O₂ reduction at 924 mol H₂O₂ molcat⁻¹ h⁻¹ while allowing recovery and reuse of the amphiphile catalyst. Integrating molecular catalysts into amphiphiles that predictively self-assemble at electrodes to program microenvironments around catalytic sites, our study showcases electrode-orthogonal non-covalent self-assembly as a molecularly tunable construct to enhance electrocatalysis.