Engineering Dynamic Proton “Hubs” in Hydrogen‐Bonded Frameworks for Superprotonic Conductivity

Abstract

ABSTRACT Mimicking the synergistic proton conduction in biology remains a formidable challenge for synthetic materials. Here, we report a strategic approach by engineering dynamic proton “hubs” within hydrogen‐bonded organic frameworks (HOFs). These hubs are supramolecular secondary building units (SSBUs) formed by charge‐assisted hydrogen bonds between ammonium and sulfonate groups, which are programmed into the frameworks to direct proton traffic. The resulting ammonium‐sulfonate HOF, BPDS_NH 4 , exhibits a highly competitive proton conductivity of 0.21 S cm −1 (90°C, 90% RH). The exceptional performance is governed by the dual function of the proton hubs: their high charge density and hydrophilicity create a highway for vehicular transport of solvated proton clusters (H + (H 2 O) n ), while the dense, dynamic H‐bonded network within each hub serves as a confined arena for ultrafast Grotthuss hopping. These processes are synergistically coupled, as verified by activation energy analysis and H/D isotope effect. This work establishes the construction of supramolecular proton hubs as a versatile blueprint for the rational design of advanced proton‐conducting materials.