Polymer-derived carbon architectures for multifunctional ORR/OER/HER electrocatalysis: From molecular precursors to active-site engineering

Efficient and durable electrocatalysts are central to the realization of sustainable energy conversion and storage technologies, including water electrolyzers and metal–air batteries. Polymer-derived carbon (PDC) materials, obtained from biopolymers, synthetic polymers, and metal-organic polymers, have emerged as versatile platforms for multifunctional electrocatalysis. Their compositional diversity, controllable heteroatom doping, hierarchical porosity, and tunable electronic structure enable precise modulation of catalytic active sites and mass/electron transport pathways. This review establishes a unified framework that correlates precursor chemistry, carbonization pathways, and structural evolution with catalytic functionality toward oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). We systematically analyze synthetic strategies—including templating, in situ metal coordination, and polymer–metal hybridization—together with advanced characterization approaches that elucidate active-site configuration, defect chemistry, and interfacial phenomena. Particular emphasis is placed on electronic structure modulation, heteroatom coordination environments (e.g., M–N–C motifs), surface reconstruction under operating conditions, and pH-dependent stability mechanisms governing bifunctional and trifunctional performance. By integrating mechanistic insights with structure–activity relationships, this review defines key design principles for next-generation PDC-based electrocatalysts. Finally, the review outlines critical challenges related to scalability, durability under dynamic electrochemical conditions, and operando characterization, providing strategic directions for translating polymer-derived carbon systems into practical renewable energy technologies.