Molecular-Level Structure Regulation via Sequential Pre-Crosslinking and Friedel-Crafts Hypercrosslinking: Fabrication of Bimetallic Doped Porous Carbon Electrocatalysts.

Owing to high surface inertness and insufficient active sites, traditional carbons cannot anchor and disperse metal species evenly, restricting catalytic activity. Via polymer precursor design, the components, functional groups and pore architecture can be tailored molecularly and preserved upon carbonization, thus regulating carbon microstructure, surface properties and active centers efficiently. This work focuses on the synthesis and structural tuning of polystyrene-based precursors using a three-step procedure of pre-crosslinking, Friedel-Crafts hypercrosslinking, and activation. The materials possess abundant mesopores ranging from 7 to 30 nm, which serve as an ideal platform for the efficient anchoring of metal ions and mass transfer during the subsequent carbonization and functionalization processes. Based on the strong adsorption and exchange ability of sulfonic acid groups, transition metal ions such as Co, Ni and Fe were uniformly doped on the surface of nanoparticles and carbonized at 300-600 °C in an air atmosphere to realize the conversion of the polymer skeleton to a carbon matrix and the in situ formation of metal species into oxide nanoparticles. At the application performance level, the prepared Co/Ni bimetallic-carbon-doped material exhibits excellent electrocatalytic activity in the alkaline oxygen evolution reaction. The overpotential is only 0.3478 V at a current density of 10 mA cm