Understanding the Ligand Effect on the Structural Dynamics of PtAu ₂₄ Nanoclusters Supported on CeO ₂

Abstract The water–gas shift (WGS) and CO oxidation reactions are critical in hydrogen production and environmental catalysis, with performance strongly influenced by the nanoscale structure of metal catalysts and their interaction with oxide supports. This study investigates the ligand‐directed dynamics of atomically precise PtAu 24 nanoclusters supported on cerium oxide (CeO 2 ). Three variants—Au 24 Pt protected by 2‐phenylethanethiolate (PET), 4‐ tert ‐butylbenzenethiolate (TBBT), and a mixed 4‐ tert ‐butylbenzenethiolate/thiodithiolate (TDT) ligand shell—were synthesized and tested. Although sharing a common Au 12 Pt core, differences in staple motifs and ligand architectures notably influenced catalytic behavior. In both WGS and CO oxidation reactions, the TDT‐protected cluster showed the highest activity and the lowest activation temperature. The PET‐protected cluster, while less active, displayed superior stability over consecutive cycles. Structural characterizations and kinetic studies suggest that ligand‐induced surface dynamics affect both the exposure and stability of active Pt and Au sites in the CeO 2 interface. These insights underscore the importance of ligand design in tailoring nanocluster‐based catalysts.