Origin of synergistic effects in bicomponent cobalt oxide-platinum catalysts for selective hydrogenation reaction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31519905.
- Also identified by DOI 10.1038/s41467-019-11970-8 and PMC identifier 6744570.
- 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
The synergistic nature of bicomponent catalysts remains a challenging issue, due to the difficulty in constructing well-defined catalytic systems. Here we study the origin of synergistic effects in CoO<sub>x</sub>-Pt catalysts for selective hydrogenation by designing a series of closely contacted CoO<sub>x</sub>Pt/TiO<sub>2</sub> and spatially separated CoO<sub>x</sub>/TiO<sub>2</sub>/Pt catalysts by atomic layer deposition (ALD). For CoO<sub>x</sub>/TiO<sub>2</sub>/Pt, CoO<sub>x</sub> and platinum are separated by the walls of titania nanotubes, and the CoO<sub>x</sub>-Pt intimacy can be precisely tuned. Like CoO<sub>x</sub>Pt/TiO<sub>2</sub>, the CoO<sub>x</sub>/TiO<sub>2</sub>/Pt shows higher selectivity to cinnamyl alcohol than monometallic TiO<sub>2</sub>/Pt, indicating that the CoO<sub>x</sub>-Pt nanoscale intimacy almost has no influence on the selectivity. The enhanced selectivity is ascribed to the increased oxygen vacancy resulting from the promoted hydrogen spillover. Moreover, platinum-oxygen vacancy interfacial sites are identified as the active sites by selectively covering CoO<sub>x</sub> or platinum by ALD. Our study provides a guide for the understanding of synergistic nature in bicomponent and bifunctional catalysts.