Efficient CO2 Electroreduction by Highly Dense and Active Pyridinic Nitrogen on Holey Carbon Layers with Fluorine Engineering

Electrocatalytic CO2 reduction by metal-free nitrogen-doped carbon (N-C) catalysts provides a solution for CO2 reuse; however, it suffers a large overpotential and poor selectivity due to the low intrinsic reactivity of N dopants. Herein, we report the promotion of CO2 reduction on N-C through the integration of increasing the numbers and inherent catalytic reactivity and selectivity of pyridinic N dopants. A novel sacrificial soft-templating approach was developed to construct a two-dimensional holey carbon nanostructure to preferentially host dense edge-located pyridinic N, and electron rich fluorine (F) was simultaneously incorporated to activate pyridinic N sites by engineering their electronic properties. Consequently, the resultant N,F-codoped holey carbon layers achieve a CO Faradaic efficiency of 90% at a low overpotential of 490 mV for 40 h without decay, significantly surpassing the F-free N-C counterpart. Density functional theory (DFT) calculations reveal that the electron donation from a nearby F atom increases the charge density and delocalizes electronic density of states of pyridinic N. These electronic benefits thus greatly promote the CO2 activation on the highly dense and active pyridinic N sites by facilitating the electron transfer and strengthening the binding interaction with *COOH intermediate. The discovery of dopant-induced synergistic interaction may create a path for manipulating catalytic CO2 reduction properties.