A Mn-N₃ single-atom catalyst embedded in graphitic carbon nitride for efficient CO₂ electroreduction.

ABSTRACT: Developing effective catalysts based on earth abundant elements is critical for CO₂ electroreduction. However, simultaneously achieving a high Faradaic efficiency (FE) and high current density of CO (j_CO) remains a challenge. Herein, we prepare a Mn single-atom catalyst (SAC) with a Mn-N₃ site embedded in graphitic carbon nitride. The prepared catalyst exhibits a 98.8% CO FE with a j_CO of 14.0?mA?cm^-2 at a low overpotential of 0.44?V in aqueous electrolyte, outperforming all reported Mn SACs. Moreover, a higher j_CO of 29.7?mA?cm^-2 is obtained in an ionic liquid electrolyte at 0.62?V overpotential. In situ X-ray absorption spectra and density functional theory calculations demonstrate that the remarkable performance of the catalyst is attributed to the Mn-N₃ site, which facilitates the formation of the key intermediate COOH^* through a lowered free energy barrier.

SUBMITTER: Feng J 

PROVIDER: S-EPMC7455739 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature