3D printing-enabled synthesis of N/B-co-doped porous carbon electrodes from poly (ionic liquid) for electroconversion of CO2

Exploiting its exceptional structural tunability and digital manufacturing capability, 3D printing emerges as a transformative technique for the rational design and scalable fabrication of catalytic electrodes tailored for advanced electrochemical energy systems. In this study, hierarchically porous, self-supporting carbon electrodes were fabricated via 3D printing technique in combination with the sequential conformal carbonization. An optimized polymerizable ionic liquid-based ink was employed to produce a 3D printed polymer gel, which was subsequently functionalized with B-containing species. The as-prepared gel was then pyrolyzed to yield B/N-co-doped carbon electrodes with a high surface area possessing micropores, mesopores and macropores. The metal-free cathode demonstrated good performance in electrocatalytic CO 2 reduction, producing syngas with tunable H 2 /CO ratios ranging from 0.37 to 2.6, thereby catering to diverse application requirements. This study naturally integrates 3D printing with ionic-liquid chemistry to fabricate customizable metal-free carbon electrodes for efficient CO 2 -to-syngas conversion, offering a Power-to-X route to store intermittent renewable electricity as chemical energy and to deliver tunable H 2 /CO syngas suitable for downstream fuel and chemical synthesis. • Self-supporting carbon electrode for CO 2 RR is developed by 3D printing. • 3D printing is based on photopolymerization using ionic liquid-based ink. • The hierarchically porous 3Dp-H-BNC has a high S BET of 842 m 2 g -1 . • Composition of as-produced syngas can vary from 0.4 to 2.6 (H 2 / CO).