The exposed facets of a support critically govern the performance of supported metal catalysts, yet their atomic-scale regulatory mechanisms remain unclear. This study employs multiscale simulations to elucidate how three low-index CeO2 facets(111), (110), and (100)regulate the structure, stability, and catalysis of supported sub‑nanometer Cu clusters (Cun, n = 2−10) for the water−gas shift reaction (WGSR). A multistep structure screening approach, combining machine learning molecular dynamics (MLMD) and DFT calculations, reveals that the metal−support interaction (MSI) strength follows the order (111) Cu2/CeO2(110) > Cu2/CeO2(100). Carboxyl formation is identified as the rate‑determining step on (111) and (110), while a high barrier for H2 formation limits the activity on the (100) facet. This work provides a detailed atomic‑scale picture of the “structure → MSI → dispersion → performance” relationship, revealing that overall catalytic performance is governed by a trade-off between thermodynamic stability (governing the abundance of active species) and kinetic factors (intrinsic activity and sintering resistance). CeO2(110) optimally balances this trade-off, offering moderate cohesion energy to stabilize small clusters without triggering detrimental over-dispersion or thermodynamically driven sintering. These insights offer key guidelines for rational design of supported catalysts via facet control.
Zhu et al. (Thu,) studied this question.