Transition metal doped pyrrole-NC for high-performance CO2 reduction reaction to C1 products

The electrochemical CO2 reduction reaction (CO2RR) provides a potential to mitigate excessive carbon emission and achieve carbon neutrality eventually. Herein, 26 transition metal anchored pyrrole nitrogen doped carbon catalysts (TM-NCs) were proposed as high-performance single atom catalysts (SACs) for CO2RR via a multi-level screening. The results revealed that 23 out of the 26 TM-NCs possessed superior thermodynamic and electro-chemical stability, and 11 TM-NCs exhibited preferred CO2RR selectivity over the side reactions. The reaction pathways of CO2RR to C1 products, including CO, HCOOH, CH3OH, and CH4, on TM-NCs were explored. Considering the activity and product selectivity along CO2RR, Cr/Mn/Co-NCs were screened out as outstanding SACs in CO2RR to HCOOH with low limiting potentials of -0.18 to -0.10 V, which surpassed most previously reported SACs. With the applied potentials over -0.6 V, Cr/Mn/Co-NCs exhibited the advantages of yielding high-throughput reaction products of CH4. The coordinated N-type analysis demonstrated that compared with pyridine-type TM-NCs, pyrrole-type TM-NCs possessed weaker binding strengths with intermediates but better or comparable CO2RR activity. The results of this work highlighted pyrrole-type Cr/Mn/Co-NCs as ideal SACs for CO2RR and uncovered the effect of coordinated N-type in TM-NCs on CO2RR performance.