Structural factors of Au₂₅ cluster as precursor to synthesize Au/Nb2O5 for low-temperature CO oxidation
J. Hong,X. Bai, X. Wang, H Ishikawa,T. Murayama, S. Yamazoe, G. Xiu, T. Ishida, M. Lin
Catal. Today, 459, 115415 (2025).
Gold (Au) catalysts have gained significant attention as effective materials for the low-temperature oxidation of carbon monooxide (CO), with their electronic and geometric structures playing a key role in regulating oxidative properties. A series of Au catalysts were prepared using well-defined Au clusters (Au25(SC12H25)18) as precursor, and the effects of structural factors on the CO oxidation activity of these catalysts were investigated, including the size of Au nanoparticles, the ligand removal percentage, and the proportion of Auδ+/Au0. This work unveiled that the appropriate removal of ligands can improve the catalytic performance for CO oxidation. Moreover, the size of Au nanoparticles is negative correlation with the CO oxidation activity over Au/Nb2O5 catalysts with Au25(SC12H25)18 as a precursor or on the Au/Nb2O5 catalysts with Aun(SC12H25)m (m/n = 0.46) as a precursor, but the effect was more pronounced in the Au-based catalysts with precise atomic precursors. The prepared Au/Nb2O5 catalyst that was calcined at 300 °C exhibited excellent CO oxidation activity (T50 %, the temperature at 50 % CO conversion) at 18 °C due to the small Au nanoparticle side and minimum residue of thiol ligand. We anticipate that this study will stimulate novel perspectives and contribute to the development of highly efficient and stable Au-based catalyst systems.