Ni Wenpeng, Liu Zhixiao, Zhang Yan, Ma Chao, Deng Huiqiu, Zhang Shiguo, Wang Shuangyin
College of Materials Science and Engineering, State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, 410004, China.
School of Physics and Electronics, Hunan University, Changsha, Hunan, 410082, China.
Adv Mater. 2021 Jan;33(1):e2003238. doi: 10.1002/adma.202003238. Epub 2020 Nov 26.
Manipulating the in-plane defects of metal-nitrogen-carbon catalysts to regulate the electroreduction reaction of CO (CO RR) remains a challenging task. Here, it is demonstrated that the activity of the intrinsic carbon defects can be dramatically improved through coupling with single-atom Fe-N sites. The resulting catalyst delivers a maximum CO Faradaic efficiency of 90% and a CO partial current density of 33 mA cm in 0.1 m KHCO The remarkable enhancements are maintained in concentrated electrolyte, endowing a rechargeable Zn-CO battery with a high CO selectivity of 86.5% at 5 mA cm . Further analysis suggests that the intrinsic defect is the active sites for CO RR, instead of the Fe-N center. Density functional theory calculations reveal that the Fe-N coupled intrinsic defect exhibits a reduced energy barrier for CO RR and suppresses the hydrogen evolution activity. The high intrinsic activity, coupled with fast electron-transfer capability and abundant exposed active sites, induces excellent electrocatalytic performance.
调控金属-氮-碳催化剂的面内缺陷以调节CO的电还原反应（CO RR）仍然是一项具有挑战性的任务。在此，证明了通过与单原子Fe-N位点耦合，可以显著提高本征碳缺陷的活性。所得催化剂在0.1 m KHCO中提供了90%的最大CO法拉第效率和33 mA cm的CO分电流密度。在浓电解质中保持了显著的增强效果，赋予可充电锌-CO电池在5 mA cm时86.5%的高CO选择性。进一步分析表明，本征缺陷是CO RR的活性位点，而不是Fe-N中心。密度泛函理论计算表明，Fe-N耦合的本征缺陷对CO RR表现出降低的能垒，并抑制析氢活性。高本征活性，加上快速的电子转移能力和丰富的暴露活性位点，诱导出优异的电催化性能。
