Related Experiment Video
Updated: Feb 19, 2026
11:17
Spark Plasma Sintering Apparatus Used for the Formation of Strontium Titanate Bicrystals
Published on: February 9, 2017
10.3K
Ostwald ripening versus single atom trapping: towards understanding platinum particle sintering
Xing Wang1, Jeroen A van Bokhoven, Dennis Palagin
1Institute for Chemical and Bioengineering, ETH Zurich, Vladimir Prelog Weg 1, 8093 Zurich, Switzerland. jeroen.vanbokhoven@chem.ethz.ch.
Physical Chemistry Chemical Physics : PCCP
|November 9, 2017
Summary
Platinum catalysts degrade via Ostwald ripening. This study shows ceria surfaces trap platinum oxide species, forming stable, single-atom catalysts resistant to sintering at high temperatures.
Area of Science:
- Catalysis
- Materials Science
- Surface Chemistry
Background:
- Ostwald ripening degrades platinum group catalysts at high temperatures in oxidizing environments.
- Volatile platinum species are implicated in catalyst deactivation.
- Atomically dispersed catalysts offer enhanced activity and stability.
Purpose of the Study:
- Investigate the interaction of platinum oxide (PtO2(g)) with ceria (CeO2) and alumina (Al2O3) surfaces.
- Understand the mechanism of single-atom trapping on ceria surfaces.
- Identify strategies for developing sinter-resistant catalysts.
Main Methods:
- Comparative density functional theory (DFT) study.
- Analysis of PtO2(g) interaction with defect-free and stepped CeO2(111) surfaces.
- Modeling of PtO2(g) interaction with Al2O3(100) surfaces.
Main Results:
- Defect-free CeO2(111) and Al2O3(100) surfaces exhibit low binding energy for PtO2(g), promoting particle growth.
- Stepped edges of CeO2(111) surfaces effectively trap mobile PtO2(g) species.
- Atomically dispersed platinum catalysts on ceria form stable square-planar [PtO4] structures, preventing aggregation.
Conclusions:
- Ceria stepped edges can trap volatile platinum species, forming single-atom catalysts.
- The strong binding of platinum to ceria prevents nanoparticle formation and sintering.
- This mechanism offers a pathway for designing highly stable, sinter-resistant catalysts.
