Nitrogen-doped carbon with high graphitic-N exposure for electroreduction of CO2 to CO

Application of nitrogen-doped carbon for electroreduction of CO 2 to CO receives increasing attentions, and improving the CO selectivity of carbon-based materials is prominent. Here we introduce a halogen-assisted calcination strategy for constructing two-dimensional (2D) nitrogen-doped carbon from ZIF-8 precursor. Benefitting from the abundant graphitic-N (G-N) and the enlargement of electrochemical surface area (ECSA), 2D nitrogen-doped carbon presents excellent catalytic activity with the high faradaic efficiency (FE) of CO reaching 99.5% and current density of −2.6 mA cm −2 at a low potential of −0.5 V (vs. RHE) in H-type cell, with the long-term stability up to more than 20 h. A positive correlation between FECO and the ratio of G-N (the ratio of graphitic-N content to total N content.) is revealed. The halogen-assisted calcination can effectively increase the G-N ratio and enlarge ECSA, thereby increasing FE CO , which is a promising strategy for improving CO selectivity of carbonaceous materials. Graphical abstract