Atomically precise gold nanoclusters for CO oxidation: balancing activity and stability by ligand shedding

Abstract

The use of ligand-protected gold clusters for catalysis has been extensively researched in catalysis due to their excellent properties, stability, and ability to maintain a precise atomic number. However, the role of ligand effects in the catalytic process remains unclear. Therefore, there is a need to understand how ligands modulate the electronic structure and catalytic properties of gold clusters. In this study, we selected four experimentally produced phosphorus ligand-protected gold clusters ([Au9(PPh3)8]3+, [Au10(PPhCy2)6Cl3]+, [Au11(PPh3)8Cl2]+, and [Au13(PMe2Ph)10Cl2]3+). We performed first-principles calculations to investigate the changes in the geometry and electronic structure of these clusters during the shedding of ligands. In addition, we characterized their catalytic properties using CO oxidation reactions. Our results show that the small-sized ligand-protected gold clusters exhibit an evolutionary trend towards a planar structure with the shedding of ligands. The d orbital centers and O2 adsorption of these clusters also exhibit a unique linear relationship. Furthermore, these ligand clusters exhibit excellent CO oxidation activity through both L-H and E-R mechanisms, with several representative catalytic reactions having reaction barriers ranging from 0.38 eV to 0.78 eV. The catalytic activity demonstrates a distinct relationship with the adsorption energy and d orbital centers. Importantly, our findings suggest that it is possible to regulate the geometry, electronic structure, and catalytic activity of ligand-protected gold clusters.

Computational design of spatially confined triatomic catalysts for nitrogen reduction reaction

“…As shown in Figure 3F, the adsorption energy of N 2 is linearly related to the d-orbital center (ε d ) of the metal clusters. The higher the d orbital center of the TM 3 @C 3 N 3 system, the more favorable its interaction with the π* orbital of N 2 and provides more charge transfer to the N 2 molecule, thus showing a stronger binding capacity for N 2 adsorption [69][70][71][72] . Guided by these essential parameters, the catalytic response of TM trimer clusters can be finely regulated and manipulated by designing moderate cluster-carrier interactions through the selection of suitable metal elements.…”