Fe nanoparticles embedded in N-doped porous carbon for enhanced electrocatalytic CO2 reduction and Zn-CO2 battery

The selective electrochemical reduction of CO 2 to CO is a promising solution for the design of carbon-neutral, sustainable processes. Achieving a highly selective single reduction product is still challenging because of the energetically favorable competing hydrogen evolution reaction. We report the fabrication of N-doped sponge-like porous graphitic carbon structures embedded with Fe nanoparticles (Fe@NPC) via the pre-modification of a metal-organic framework (IRMOF-3(Zn)) with carboxyferrocene, followed by pyrolysis . The as-prepared Fe@NPC exhibited a 96.4% CO Faradaic efficiency at –0.5 V RHE and good stability. The exceptional CO 2 reduction performance is attributed to the unique structure of the composite catalyst, which provides abundant hierarchical pores that increase CO 2 adsorption and mass transfer, and active Fe sites that synergistically accelerate the kinetics of CO generation. The in situ attenuated total reflectance-Fourier transform infrared analysis provided proof of the improved ability of Fe@NPC to accumulate the crucial intermediate *COOH compared with other pyrolyzed porous carbons. Fe@NPC was used in a Zn-CO 2 battery that delivered a maximum power density of 3.0 mW cm –2 , evidencing its potential for application in energy-converting devices.