Graphitic-N highly doped graphene-like carbon: A superior metal-free catalyst for efficient reduction of CO2
Jingjing Li, Wenyan Zan, Hongxing Kang, Zhengping Dong, Xiaoming Zhang, Xiaoming Zhang, Yixiong Lin, Yuewen Mu, Fengwei Zhang, Xian‐Ming Zhang, Xian‐Ming Zhang, Jing Gu
Abstract
For metal-free nitrogen(N)-doped carbon catalysts, diverse N-bearing species embedded in the carbon framework are generally regarded as chemical promoters that can upgrade their catalytic performance for CO2 electroreduction reaction (CO2RR). However, it is still a controversy as to which N species plays a dominant role. Herein, a type of large surface area (371 m2/g), N-rich (11.0 wt%) graphene-like carbon electrocatalyst (NG-1000) is fabricated via facile pyrolysis from a precursor composite of dicyandiamide and phthalocyanine. The N-species in the NG-T (T = 700–1000 °C) can be fine-tuned, thus facilitating differentiating functions of the various N-species. Based on the comprehensive analysis of original Pc/CNTs and NG-T catalysts, we identified that the C atoms next to the graphitic-N species in NG-1000 serves as the main active species for CO2RR. In addition, such a non-metal based electrocatalyst is capable of achieving an excellent selectivity of 95.0 % at −0.72 V versus RHE to convert CO2 into CO, with a CO current density of 9.07 mA cm−2, comparable to the state-of-the-art metal-based electrocatalysts.