Promoting industrial-level CO2 electroreduction kinetics via accelerating proton feeding on a metal-free aerogel electrocatalyst. (January 2023)

• Record Type: Journal Article
• Authors: Zheng, Wanzhen; Wang, Dashuai; Zhang, Yikai; Zheng, Sixing; Yang, Bin; Li, Zhongjian; Rodriguez, Raul D.; Zhang, Tao; Lei, Lecheng; Yao, Siyu; Hou, Yang
• Is Part Of: Nano energy. Volume 105(2023)
• Publication Date: 2023-01
• Subjects: Metal-free carbon aerogels -- N/P doping -- Accelerating proton feeding -- CO2 electroreduction -- Zn-CO2 battery; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2022.107980
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Developing cost-effective carbon based electrocatalysts with high activity and selectivity for CO2 reduction reaction (CO2 RR) at industrial current density still remains challenges. Herein, we present a metal-free 3D cross-linked carbon aerogel catalyst containing homogeneously dispersed N and P sites (P@NCA) synthesized via freeze drying and subsequent carbonization. Benefit from the synergistic effect of N and P atoms, P@NCA aerogel delivers an excellent CO2 RR activity featured by a wide potential window from − 0.3 V to − 0.9 V with CO Faradaic efficiency (FE) of above 90 %. Importantly, a high CO FE of 85 % at an industrial current density of 100 mA cm −2 is realized. Experimental explorations and in-situ spectroelectrochemistry analyses reveal that pyrrolic-N species acts as the real active site to execute CO2 RR, while the P species facilitates the protonation process of *CO2 to *COOH intermediate by accelerating the proton feeding from water dissociation. Theoretical calculations demonstrate a suppressed *H adsorption and a facilitated *CO desorption step on pyrrolic-N site with P doping, boosting the whole CO2 RR process. Further, a rechargeable Zn-CO2 battery constructed with P@NCA aerogel as cathode delivers a maximal power density of 0.8 mW cm −2 and a superior stability. Graphical Abstract: A metal-free N/P co-doped 3D cross-linked carbon aerogel was synthesized for catalyzing the CO2 -to-CO conversion at industrial-level current density, in which the P atoms accelerate the water dissociation and boost the proton transfer, thus assisting the CO2 RR on active pyrrolic-N sites. ga1 Highlights: A metal-free N/P co-doped 3D cross-linked carbon aerogel (P@NCA) was fabricated. The P@NCA exhibited high activity and selectivity for CO2 RR at industrial-level current density. The pyrrolic-N species acted as active sites for CO2 RR, while P atoms contributed to fast proton transfer. The facilitated *COOH formation and *CO desorption on pyrrolic-N site with P doping boosted the whole CO2 RR process.