Wide Potential CO2-to-CO Electroreduction Relies on Pyridinic-N/Ni–Nx Sites and Its Zn–CO2 Battery Application

Although metal–N-doped carbons are promising electrocatalysts for CO 2 -to-CO conversion due to their high conversion efficiency and current density, their commercial application is still challenging due to their narrow potential/current range. In general, a wide potential/current electrocatalyst is in high demand for industrial CO 2 electrocatalysis. Controllable strategy to tune N configurations toward pyridinic-enriched metal–N x active sites is attractive. The synergetic effect of the ability of pyridinic N to capture Lewis acidic CO 2 and the characteristics of Ni–N active sites to inhibit the hydrogen evolution reaction (HER) can achieve a wide potential window, which has high practical value. Herein, the well-chosen precursors resulting in a pyridinic-enriched Ni–N x site can selectively catalyze CO 2 toward CO generation in aqueous media with a high Faradaic efficiency (FE) of 100% with an overpotential of 680 mV. Continuous CO FE > 90% was recorded under a wide range of potentials without decay. Motivated by its practical characteristics in CO 2 electrocatalysts, a Zn–CO 2 battery is assembled achieving a CO 2 –CO conversion efficiency of more than 90% in a wide discharge current window. Therefore, the results highlight that pyridinic-enriched Ni–N x holds great promise as simultaneous CO-selective electrocatalyst by suitably tuning M–N configurations as new perspective strategy.