Single-atom-Ni-decorated, nitrogen-doped carbon layers for efficient electrocatalytic CO2 reduction reaction

Efficient selective electroreduction of carbon dioxide into energy-dense carbonaceous fuel products is highly desirable to mitigate environmental and energy-related problems. However, there is still a need to design an electrocatalyst with high selectivity and stability towards the CO2 reduction reaction (CRR). Here, we present the promising performance of single-atom-Ni-decorated, nitrogen-doped carbon layers (SA-Ni@NC) as an efficient electrocatalyst for CRR. In this catalyst the Ni atoms are atomically dispersed and most have three-fold coordination with the N atoms in the carbon layers. Theoretical calculations show that the Ni-N-3-C site can act as a highly active site for the reduction of CO2 owing to the low energy barrier for the formation of *COOH intermediates. As a consequence, SA-Ni@NC exhibits a high Faradaic efficiency (up to 86.2%) for the production of CO at a potential of -0.6 V versus the reversible hydrogen electrode. Moreover, this simple method can also be used to produce a range of single-atom catalysts (such as SA-Co@NC). In view of the large family of zeolite imidazolate frameworks, we anticipate that our strategy will be extended to a variety of single-atom-decorated, nitrogen-doped carbon layers with a broad range of applications in energy conversion systems.