Atomically dispersed non-noble Cu dimer anchored on a novel graphitic carbon nitride as a promising catalyst for the conversion of CO to CH2CH2

Electroreduction of CO (CORR) to C-2 species with high volumetric energy densities and valuable has drawn increasing attractions recently. The high C-C coupling energy barrier and low selectivity, however, are the grand challenges for the large-scale application of the present CORR catalysts. Herein, a series of transition-metal (TM) dimers anchored on a novel two-dimensional (2D) graphitic carbon nitride (C:N = 1:1) as CORR catalysts has been explored by employing the density functional theory method. Based on the free energy changes and kinetic energy barriers, Ti-2@CN and Cu-2@CN were screened out as promising catalysts. Extensive reaction pathways were examined on Ti-2@CN, where CO can be reduced to CH3CH2OH via two competitive pathways. Intriguingly, for Cu-2@CN, CO only coverts to CH(2)CH(2 )with a low limiting potential (-0.47 V) and a small C-C coupling barrier (1.16 eV), revealing the high activity and selectivity for C-2 species. Moreover, the high binding energy coupled with the ab initio molecular dynamics (AIMD) simulations ensured the structural stability and feasibility for future experimental synthesis. These results clearly unveiled that TM dimers anchored on the 2D graphitic carbon nitride could be promising CORR catalysts in yielding C-2 products, which is beneficial for the sustainable development and energy conversion.