CO₂ electroreduction performance of PtS₂ supported single transition metal atoms: a theoretical study

Electrocatalytic CO₂ reduction is a sustainable strategy to convert CO₂ into valuable carbon products. Atomically dispersed single-atom catalysts (SACs) have great potential as effective electrocatalysts for the CO₂ reduction reaction (CO₂RR). Transition metal dichalcogenides (TMDs) are considered to be a kind of promising SAC supports. In this work, ten different 3d TM single atoms (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn) embedded in PtS₂ with single S-vacancy (TM-PtS₂) were designed by density functional theory (DFT) as candidate electrocatalysts for the CO₂RR. Possible reaction pathways of CO₂ reduction to different C₁ products were systematically investigated. The results show that for all these TM-PtS₂ SACs, higher selectivity was achieved for CO₂ reduction to C₁ products than for the competing hydrogen evolution. HCOOH is the most favorable reduction product on PtS₂-S_v supported Sc, Ti, V, Cr, Mn, Fe and Cu SACs, while multiple C₁ products are generated on Co-, Ni- and Zn-PtS₂. In particular, it is found that Sc-, V-, Fe-, Co- and Cu-PtS₂ exhibit higher electrocatalytic performance for the CO₂RR than Cu(211). Therefore, these five SACs are promising CO₂RR electrocatalysts.