Theoretical study of transition metal-doped β borophene as a new single-atom catalyst for carbon dioxide electroreduction.

The electrocatalytic carbon dioxide reduction reaction (CORR) presents a viable and cost-effective approach for the elimination of CO by transforming it into valuable products. Nevertheless, this process is impeded by the absence of exceptionally active and stable catalysts. Herein, a new type of electrocatalyst of transition metal (TM)-doped β-borophene (TM@β-BM) is investigated density functional theory (DFT) calculations. Through comprehensive screening, two promising single-atom catalysts (SACs), Sc@β-BM and Y@β-BM, are successfully identified, exhibiting high stability, catalytic activity and selectivity for the CORR. The C products methane (CH) and methanol (CHOH) are synthesized with limiting potentials () of -0.78 V and -0.56 V on Sc@β-BM and Y@β-BM, respectively. Meanwhile, CO is more favourable for reduction into the C product ethanol (CHCHOH) compared to ethylene (CH) C-C coupling on these two SACs. More importantly, the dynamic barriers of the key C-C coupling step are 0.53 eV and 0.73 eV for the "slow-growth" sampling approach in the explicit water molecule model. Furthermore, Sc@β-BM and Y@β-BM exhibit higher selectivity for producing C compounds (CH and CHOH) than C (CHCHOH) in the CORR. Compared with Sc@β-BM, Y@β-BM demonstrates superior inhibition of the competitive hydrogen evolution reaction (HER) in the liquid phase. These results not only demonstrate the great potential of SACs for direct reduction of CO to C and C, but also help in rationally designing high-performance SACs.