Xu Zhen, Mapstone Grace, Coady Zeke, Wang Mengnan, Spreng Tristan L, Liu Xinyu, Molino Davide, Forse Alexander C
Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom.
Department of Chemical Engineering, Imperial College London, London, United Kingdom.
Nat Commun. 2024 Sep 8;15(1):7851. doi: 10.1038/s41467-024-52219-3.
Supercapacitors are emerging as energy-efficient and robust devices for electrochemical CO capture. However, the impacts of electrode structure and charging protocols on CO capture performance remain unclear. Therefore, this study develops structure-property-performance correlations for supercapacitor electrodes at different charging conditions. We find that electrodes with large surface areas and low oxygen functionalization generally perform best, while a combination of micro- and mesopores is important to achieve fast CO capture rates. With these structural features and tunable charging protocols, YP80F activated carbon electrodes show the best CO capture performance with a capture rate of 350 mmol kg h and a low electrical energy consumption of 18 kJ mol at 300 mA g under CO, together with a long lifetime over 12000 cycles at 150 mA g under CO and excellent CO selectivity over N and O. Operated in a "positive charging mode", the system achieves excellent electrochemical reversibility with Coulombic efficiencies over 99.8% in the presence of approximately 15% O alongside stable cycling performance over 1000 cycles. This study paves the way for improved supercapacitor electrodes and charging protocols for electrochemical CO capture.
超级电容器正成为用于电化学二氧化碳捕获的节能且耐用的装置。然而，电极结构和充电协议对二氧化碳捕获性能的影响仍不明确。因此，本研究建立了不同充电条件下超级电容器电极的结构-性能-性能相关性。我们发现，具有大表面积和低氧官能化的电极通常表现最佳，而微孔和介孔的组合对于实现快速二氧化碳捕获速率很重要。凭借这些结构特征和可调充电协议，YP80F活性炭电极在300 mA g的二氧化碳条件下表现出最佳的二氧化碳捕获性能，捕获速率为350 mmol kg h，电能消耗低至18 kJ mol，在150 mA g的二氧化碳条件下具有超过12000次循环的长寿命，并且对氮气和氧气具有出色的二氧化碳选择性。在“正充电模式”下运行，该系统在存在约15%氧气的情况下实现了超过99.8%的库仑效率的出色电化学可逆性，以及超过1000次循环的稳定循环性能。本研究为改进用于电化学二氧化碳捕获的超级电容器电极和充电协议铺平了道路。
