Resolving the puzzle of single-atom silver dispersion on nanosized γ-Al<sub>2</sub>O<sub>3</sub> surface for high catalytic performance.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31988282.
- Also identified by DOI 10.1038/s41467-019-13937-1 and PMC identifier 6985108.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Ag/γ-Al<sub>2</sub>O<sub>3</sub> is widely used for catalyzing various reactions, and its performance depends on the valence state, morphology and dispersion of Ag species. However, detailed anchoring mechanism of Ag species on γ-Al<sub>2</sub>O<sub>3</sub> remains largely unknown. Herein, we reveal that the terminal hydroxyls on γ-Al<sub>2</sub>O<sub>3</sub> are responsible for anchoring Ag species. The abundant terminal hydroxyls existed on nanosized γ-Al<sub>2</sub>O<sub>3</sub> can lead to single-atom silver dispersion, thereby resulting in markedly enhanced performance than the Ag cluster on microsized γ-Al<sub>2</sub>O<sub>3</sub>. Density-functional-theory calculations confirm that Ag atom is mainly anchored by the terminal hydroxyls on (100) surface, forming a staple-like local structure with each Ag atom bonded with two or three terminal hydroxyls. Our finding resolves the puzzle on why the single-atom silver dispersion can be spontaneously achieved only on nanosized γ-Al<sub>2</sub>O<sub>3</sub>, but not on microsized γ-Al<sub>2</sub>O<sub>3</sub>. The obtained insight into the Ag species dispersion will benefit future design of more efficient supported Ag catalysts.