Electrocatalytic CO2 reduction reaction (ECO2RR) is not only conducive to achieve its carbon peak and neutrality targets, but also as an effective energy conversion scheme, has attracted more and more attention from scientists. In many catalysts, the Cu-based catalysts is one of the most promising catalysts for its advantages in the selective preparation of alcohols. However, currently few catalysts can efficiently select different liquid-phase products at different voltages.
In a paper published on ACS Appl. Mater. Interfaces recently, a collaborated research team led by Prof. WANG Hui from High Magnetic Field Laboratory, Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Science (CAS) reported the synthesis of ultrasmall Cu nanocrystals embedded in nitrogen-doped carbon nanosheets (Cu/NC-NSs) for selective CO2 electroreduction by adjusting the potential.
In this paper, electrocatalytic performance of Cu/NC-NSs in 1 M KOH electrolyte solution to evaluate ECO2RR using flow cell structure. At -0.37 V vs RHE, the FE of ethanol reached ～43.7%, and when the potential reached -0.77 V vs RHE, the formate was the only liquid-phase product with the FE of 63.5%.
In addition, the FE of the products did not change significantly after 16 h of continuous operation at -0.37 and -0.77 V vs RHE, indicating the excellent stability of the Cu/NC-NSs catalyst. It also has been proved by DFT calculation and the controlled experiments that the synergistic effect formed by nitrogen-doped carbon and highly dispersed copper atoms.
This work was supported financially by National Natural Science Foundation of China (21972145), Hefei Municipal Natural Science Foundation (2021009), High Magnetic Field Laboratory of Anhui Province (AHHM-FX-2021-04), Key Lab of Photovoltaic and Energy Conservation Materials of Chinese Academy of Sciences (Grant PECL2019QN004), Hong Kong Scholars Program (XJ2019022), and the Fundamental Research Funds for the Central Universities (WK2060000032). The DFT calculations were completed on the supercomputing system in the Supercomputing Center of the University of Science and Technology of China (USTC).
Schematic diagram of electrocatalytic CO2 reduction reaction of Cu/NC-NSs to prepare liquid-phase products. (Image by MENG Xiangfu)