Highly efficient electrochemical carbon dioxide reduction to syngas with tunable ratios over pyridinic- nitrogen rich ultrathin carbon nanosheets

Bing Wei; Jinhui Hao; Baoxin Ge; Wei Luo; Yongfu Chen; Yusong Xiong; Longhua Li; Weidong Shi

doi:10.1016/j.jcis.2021.10.189

Highly efficient electrochemical carbon dioxide reduction to syngas with tunable ratios over pyridinic- nitrogen rich ultrathin carbon nanosheets

J Colloid Interface Sci. 2022 Feb 15;608(Pt 3):2650-2659. doi: 10.1016/j.jcis.2021.10.189. Epub 2021 Nov 3.

Authors

Bing Wei¹, Jinhui Hao¹, Baoxin Ge¹, Wei Luo¹, Yongfu Chen¹, Yusong Xiong¹, Longhua Li¹, Weidong Shi²

Affiliations

¹ School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
² School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: swd1978@ujs.edu.cn.

PMID: 34774319
DOI: 10.1016/j.jcis.2021.10.189

Abstract

Developing nonmetallic carbon-based electrocatalysts that are affordable and have high activity and stability for carbon dioxide (CO₂) reduction to syngas is a new and challenging strategy for solving the energy crisis. Here, we prepared a highly active ultrathin nitrogen (N)-doped carbon nanosheet (UNCN) electrocatalyst. By tuning the applied potential of the UNCN-900 (900 represents the carbonization temperature) electrode, we could tune the H₂/CO ratio in clean syngas within a wide range with extra-high Faradic efficiency (FE). The maximum FE_CO reached 91%, which represented the highest value among the reported nonmetallic carbon-based electrocatalysts for CO₂ reduction to syngas. According to the results of experiments and density functional theory calculations, we proved that pyridinic-N in UNCNs-900 is the active site of the CO₂ reduction reaction (CO₂RR) and that graphitic-N may be the active site for the hydrogen evolution reaction. These results provide a useful case for electrochemical CO₂ reduction to syngas with a tunable H₂/CO ratio using nonmetallic carbon-based electrocatalysts.

Keywords: CO(2)RR; Low-cost; Nitrogen-doped carbon; Syngas.