Modulating *CO coverage via the pyrrolic-N content on carbon for enhanced electrocatalytic CO₂ reduction to CO

The electrocatalytic CO₂ reduction reaction (eCO₂RR) is a new energy technology that shows a feasible way to achieve carbon neutrality and to produce valuable fuels and feedstocks with effective electrocatalysts. Nitrogen-doped carbon (NC) materials have become the most promising carbon-based electrocatalysts to produce CO and potential metal carriers to produce multi-carbon products due to their low cost, high activity, and ability to enhance metal-carrier interactions. However, aiming at high selectivity of CO, it is important to optimize the competing coverage of *CO and *H on the NC working electrocatalyst surface. Here, for the first time, we controllably adjusted the pyrrolic-N content on NC via a simple strategy of pyrrolic-N-abundant phthalocyanine-assisted pyrolysis of a common MOF precursor (ZIF-8), which then modulated the *CO and *H coverage for enhanced electrocatalytic CO₂ reduction to CO with an FE_CO value of above 92% at −0.6 V vs. RHE. Mechanistic studies showed that the high content of pyrrolic-N of Pr-a-NC induced the surface coverage of *CO to be much higher than that of the control samples. Meanwhile, under the conditions of high *CO coverage, adsorbed *CO intermediates combined with the active *H generated the high-coverage intermediate *COH, which is one of the most common intermediates to generate multi-carbon products. So, this work not only provides an effective strategy for the future rational design of carbon electrocatalysts to generate CO, but also opens an avenue to engineer carbon-nitrogen coordination substrate-loaded metal electrocatalysts for the production of multi-carbon products from the eCO₂RR.