Dynamic Single-Atom Catalysts on Gallium To Overcome the Scaling Relationship Limit: AIMD Screening for CO2 Reduction and Hydrogen Evolution Reactions.

Extensive research has been conducted on single-atom catalysts (SACs) for a range of electrochemical reactions. However, static SACs suffer from scaling relationship limits, which hinder their further development. In this work, we introduce the idea of dynamic SACs supported on Gallium for the hydrogen evolution reaction (HER) and the CO2 reduction reaction (CO2RR). We utilized AIMD and DFT calculations to systematically conduct high-throughput screening on s-, p-, d-, and f-block elements supported by Gallium denoted as M-SAC@Ga. We found that among all the understudied catalysts, Re-, Pt-, Pd-, Rh-, Ir-, Au-, Ag-, Ru-, Tc-, Ni-, Cu-, Os-, Hg-, and Ge-SAC@Ga possess thermodynamic and electrochemical stabilities. In addition: Ni-SAC@Ga leads to CO2RR overpotentials of 0.28, 0.28, 0.69, and 0.92 V, respectively, toward CHOOH, CO, CH3OH, and CH4 formation. Low overpotentials and mitigation of scaling relationship limits are primarily due to the atomic intelligence (the ability to guide reactions) and dynamic coordination changes of SACs, seen through DFT and AIMD calculations. Analyzing the phonon-induced fluctuations in total energies suggests a standard deviation of up to 0.26 V in the calculated overpotentials. Additionally, the dephasing time for these dynamic systems is below 5 fs, a crucial factor affecting the modeling of catalytic behavior. Feature importance analysis suggests that the d-electron numbers serve as the universal descriptors for these catalysts. This study offers a comprehensive insight into the discovery of cutting-edge electrocatalysts and beyond by applying the concept of dynamic SACs.