The Impacts of Ligand Removal and Metal Doping on the Peroxidase-like Activity of Au<sub>25</sub>(SR)<sub>18</sub> Clusters
Zhou Huang, Qisheng Yan, Qing Tang
Abstract
The peroxidase-like (POD) activity of atomically precise gold nanoclusters holds immense potential for oxidative catalysis, yet the mechanistic interplay among ligand engineering, metal doping, and charge states remains elusive. Through systematic first-principles calculations, we unveil the atomic-level regulation of POD activity in [Au 25 (SCH 3 ) 18 ] q nanoclusters and their derivatives. The charge-state analysis identifies anionic [Au 25 (SCH 3 ) 18 ] − as the optimal catalyst, which weakens the O–O bond and lowers the rate-determining step (RDS) barrier to 1.43 eV. Moreover, the strategic partial ligand removal in [Au 25 (SCH 3 ) 17 ] − reshapes the catalytic pathway, shifting the RDS to the second TMB oxidation with a reduced barrier (1.20 eV) while exposing undercoordinated Au sites for efficient charge transfer. Metal doping introduces further optimization, where partially dethiolated Hg-doped [HgAu 24 (SCH 3 ) 17 ] 0 -O achieves an ultralow RDS barrier (0.51 eV) through tailored metal–oxygen interactions. Crystal orbital Hamilton population (COHP) analysis quantifies the critical role of the ICOHP/d M–O ratio in governing the catalytic activity, revealing a strong linear correlation ( R 2 = 0.89) with the activation barriers. This work establishes ligand removal and metal doping as synergistic strategies to decouple bond activation and electron transfer processes, providing a universal descriptor (ICOHP/d M–O ) for the rational design of high-performance nanozymes. Our findings would advance the functional design of gold nanoclusters for the future oxidative catalysis applications.