A theoretical investigation of SnZn dual-atom catalysts with different coordination environments for CO2 hydrogenation to HCOOH

This study investigates detailed reaction mechanisms and catalytic performance of a series of SnZnN6/G with different coordination environments (DM1, DM2, DM3, and DM4) for CO2 hydrogenation to HCOOH. To evaluate structural stability, formation energy calculations are conducted, and the calculation results show that four SnZnN6/G exhibit good stability. The research on reaction pathways shows that the optimal pathway on SnZnN6/G is CO2* + H2*→ HCOO* + H* → HCOOH*, and rate-determination step of CO2 to HCOOH is CO2* + H2*→ HCOO* + H* on SnZnN6/G. Additionally, the catalytic performance of SnZn dual-atom catalysts with different coordination environments is arranged in the following order: DM1 > DM2 > DM4 > DM3. The Mulliken charge calculation results indicate that DM1 exhibits pronounced charge fluctuations, potentially accounting for its high activity. In conclusion, it can be concluded that the modification of the coordination environment has a significant impact on the catalytic activity of dual-atom catalysts, and among the catalysts studied, DM1 stands out as a highly active catalyst for the hydrogenation of CO2 to HCOOH.