A 3D printed, metal-free, carbon-based catalytic electrode for converting CO2 into syngas

Abstract

As the CO₂ reduction reaction (CO₂RR) emerges as a promising pathway toward achieving sustainable energy utilization, 3D printing technology, as an innovative green manufacturing approach, offers significant opportunities for the customized design of CO₂RR catalytic electrodes. In this study, leveraging the principles of green chemistry, a phosphorus (P) and nitrogen (N) co-doped metal-free carbon-based catalytic electrode (3Dp-PNCE) was fabricated using 3D printing. This approach enables efficient material utilization while significantly reducing energy consumption and material waste during fabrication. By precisely controlling the electrode structure through 3D printing, the resulting design achieves an optimal geometry, effectively enhancing the CO₂RR efficiency and producing high-value syngas. Notably, the prepared 3Dp-PNCE demonstrates an adjustable H₂ : CO ratio in syngas production, ranging from 0.58 to 3.65 under applied potentials of −0.6 V to −1.0 V, fully meeting the requirements for hydrocarbon production via Fischer–Tropsch synthesis. Additionally, the 3Dp-PNCE exhibits excellent stability, maintaining 94.5% of its initial CO faradaic efficiency (FE_CO) after 10 h of continuous operation. Compared with traditional methods, the 3Dp-PNCE employs a green and sustainable design enabled by 3D printing, significantly reducing waste generation during manufacturing and further exemplifying the core principles of green chemistry. This study successfully employs 3D printing technology to achieve the green fabrication of metal-free carbon-based catalytic electrodes, providing a robust reference for the development of advanced, environmentally friendly, and efficient customized catalytic electrodes for syngas production.