Highly Efficient Porous Carbon Electrocatalyst with Controllable N-Species Content for Selective CO2 Reduction.

We report a straightforward strategy to design efficient N doped porous carbon (NPC) electrocatalyst that has a high concentration of easily accessible active sites for the CO2 reduction reaction (CO2 RR). The NPC with large amounts of active N (pyridinic and graphitic N) and highly porous structure is prepared by using an oxygen-rich metal-organic framework (Zn-MOF-74) precursor. The amount of active N species can be tuned by optimizing the calcination temperature and time. Owing to the large pore sizes, the active sites are well exposed to electrolyte for CO2 RR. The NPC exhibits superior CO2 RR activity with a small onset potential of -0.35 V and a high faradaic efficiency (FE) of 98.4 % towards CO at -0.55 V vs. RHE, one of the highest values among NPC-based CO2 RR electrocatalysts. This work advances an effective and facile way towards highly active and cost-effective alternatives to noble-metal CO2 RR electrocatalysts for practical applications.