Ag₁₀ Ti₂₈ -Oxo Cluster Containing Single-Atom Silver Sites: Atomic Structure and Synergistic Electronic Properties

Supported single-atom catalysts have been emerging as promising materials in a variety of energy catalysis applications. However, studying the role of metal-support interactions at the molecular level remains a major challenge, primarily due to the lack of precise atomic structures. In this work, by replacing the frequently used TiO₂ support with its molecular analogue, titanium-oxo cluster (TOC), we successfully produced a new kind of Ti-O material doped with single silver sites. The as-obtained Ag₁₀ Ti₂₈ cluster, containing four exposed and six embedded Ag sites, is the largest noble-metal-doped Ti-O cluster reported to date. Density functional theory (DFT) calculations show that the Ag₁₀ Ti₂₈ core exhibits properties distinct from those of metallic Ag-based materials. This Ti-O material doped with single Ag sites presents a high ϵ_d and moderate CO binding capacity comparable to that of metallic Cu-based catalysts, suggesting that it might display different catalytic performance from the common Ag-based catalysts, for example, for CO₂ reduction. These results prove that the synergism of active surface metal atoms and the Ti-O cluster support result in unique physical properties, which might open a new direction for single-atom-included catalysts.