Two-dimensional pyrite supported transition metal for highly-efficient electrochemical CO2 reduction: A theoretical screening study

Electrochemical CO2 reduction to energy-rich fuels and chemical feedstocks provides a sustainable route for the renewable energy storage and mitigation of CO2 emissions from human activity. However, the rational design of electrocatalysts with highly catalytic activity and product selectivity towards CO2 reduction remains a challenging task. Herein, the theoretical screening based on density functional theory (DFT) calculations was performed to design the two-dimensional single-atom catalysts (M@2D-FeS2) and to systematically investigate the catalytic activity of catalysts toward CO2 electroreduction. Co@2D-FeS2 shows superior catalytic activity and selectivity towards HCOOH production, and significantly suppresses the competing hydrogen evolution reaction (HER). The better HCOOH activity is associated with the lower d-band center and the localized charge distribution of transition metal atom. Ti@2D-FeS2 and V@2D-FeS2 exhibit good catalytic activity for CO production from CO2 electroreduction. Their overpotentials required for CO production are lower than that of the most active Au electrode. Ti@2D-FeS2 and V@2D-FeS2 serve as better catalysts to produce syngas. Cr@2D-FeS2 is a promising catalyst to produce CH4 from CO2 electroreduction. Cr@2D-FeS2 shows an exceptional performance for CH4 production, and outperforms the currently most active CO2RR-to-CH4 catalysts. Specifically, only a lower overpotential of 0.36 V is required to enable CO2 reduction to CH4. Cr@2D-FeS2 is also catalytically active towards C2H4 production due to the relatively lower overpotential of 0.64 V. The reduced overpotentials and excellent product selectivity could provide an encouraging motivation for experimental efforts to explore the advanced generations of highly-efficient CO2RR electrocatalysts.