Micropore Effect for Boosting Carbon Dioxide Electroreduction over Nitrogen-Doped Carbon

Le résumé fourni par la source

Carbon-based materials with abundant porosity represent a promising class of catalysts for the electrochemical reduction of carbon dioxide (CO 2 RR). Macropores and mesopores are widely regarded as essential for ensuring accessible active sites and facilitating rapid mass transport. However, the role of micropores─ubiquitous in carbon-based electrocatalysts─has often been overlooked. Herein, the influence of microporosity on CO 2 RR is investigated by designing nitrogen-doped carbon materials. Varying microporous structures were achieved through the molecular tuning of the building units of microporous organic polymers. In the aqueous electrolyte, carbon material with fewer micropores exhibited superior apparent performance. The CO selectivity and partial current density reached 93.5% and 29 mA cm –2 . However, no significant enhancement in intrinsic activity was observed. Coupled with its high specific surface area and superior wettability in nonaqueous electrolytes, the catalyst with a higher micropore content achieved the highest current density of 82 mA cm –2 at −2.4 V (vs Ag/Ag + ), along with the CO selectivity of 98.3% in acetonitrile solution of 1-butyl-2,3-dimethyl imidazolium nitrate (BMMImNO 3 ). Moreover, intrinsic activity was also enhanced by introducing more micropores. In situ spectroscopic analysis reveals that the confinement of BMMIm + within the micropores stabilizes the *COOH intermediate, thereby accelerating the conversion of *CO 2 to *COOH within the confined micropore environment. Thus, the confinement of BMMIm + within micropores contributed to enhanced intrinsic activity.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.