Self-Tethering Molecular Electrocatalysts Program Microenvironments for Enhanced H2O2 Synthesis

Electrosynthesis of H2O2 from O2 in neutral aqueous media offers direct access to this widely utilized oxidant for point-of-use applications. Yet, active-site non-uniformity of heterogeneous electrocatalysts challenges optimization of reactivity with molecular-level control. Here, we introduce a non-covalent self-tethering molecular catalyst platform to enhance H2O2 electrosynthesis, otherwise sluggish in neutral buffer. 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 three orders of magnitude. Self-tethering anthraquinone catalyzes O2 reduction at 924 mol H2O2 molcat–1 hr–1, outperforming its non-tethered counterpart, and is recoverable, leaving a neutral H2O2 solution. Integrating uniform molecular catalysts into amphiphiles that predictively self-assemble in tailored microenvironments at electrodes, our studies demonstrate non-covalent self-tethering as a molecularly tunable construct to enhance electrocatalysis.