Enhancing CO 2 RR Catalytic Activity of Graphene-Boron Nitride Heterostructures Based Single Atom Catalysts through Theoretical Design of Intrinsic Descriptor

Designing the efficient single atom catalysts (SACs) remains a hot topic in the research area of the electrochemical CO₂ reduction reaction (CO₂RR). In this study, 23 transition metals (TM) supported either on mono- or di-vacant sites of graphene-boron nitride heterostructures (TM@Bv and TM@CBv) were investigated via the density functional theory. The catalyst stability, reactant/intermediate binding behavior, and reaction mechanisms leading to CH₄ formation were systematically studied on both SACs series. By comparison, most SACs from TM@Bv are relatively poorer in catalytic performance as a result of the stronger binding strength of the key O-bonded species. For TM@CBv, CH₄ formation is led by either the formate pathway for early-TM (III_B∼VIII) or the carbonate pathway for late-TM (VIII∼I_B). Based on our findings, the limiting potential (U_L) of CH₄ formation on TM@CBv could be described through the energetics of *OCHO and *COH, from which the optimum catalysts were determined for both pathways, respectively. Furthermore, the catalytic activity of TM@CBv could be expressed as the linear function of a descriptor including several intrinsic properties of TM as well as its coordination environment. Overall, our results provide useful information about understanding the mechanism of CO₂ electroreduction and designing the efficient SACs for CO₂RR.