A Mn-N3 single-atom catalyst embedded in graphitic carbon nitride for efficient CO2 electroreduction
Jiaqi Feng, Hongshuai Gao, Lirong Zheng, Zhipeng Chen, Shaojuan Zeng, Chongyang Jiang, Haifeng Dong, Licheng Liu, Suojiang Zhang, Xiangping Zhang
Abstract
Abstract Developing effective catalysts based on earth abundant elements is critical for CO 2 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-N 3 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-N 3 site, which facilitates the formation of the key intermediate COOH * through a lowered free energy barrier.