| AVS 64th International Symposium & Exhibition | |
| Thin Films Division | Thursday Sessions |
| Session TF+MI+NS-ThA |
| Session: | ALD and Nanostructures |
| Presenter: | Jiaming Cai, Huazhong University of Science and Technology, PR China |
| Authors: | J.M. Cai, Huazhong University of Science and Technology, PR China K. Cao, Huazhong University of Science and Technology, PR China M. Gong, Huazhong University of Science and Technology, PR China B. Shan, Huazhong University of Science and Technology, PR China R. Chen, Huazhong University of Science and Technology, PR China |
| Correspondent: | Click to Email |
Platinum nanoparticles (NPs) play an important role in the catalytic applications such as conversion of automotive exhaust, fuel cells, nano sensing and so on. For most catalytic applications, sintering of Pt NPs is undesired since the coalescence decreases the number of active sites of the catalyst. Herein we report the utilization of active oxide layers to encapsulate Pt NPs to enhance sintering resistance at high working temperature. The active oxide coated catalysts have additional metal-oxide interfaces which may further improve the catalytic activity besides good sintering resistance. Nickel oxide coating layer is prepared via atomic layer deposition (ALD) method. The effect of layer thickness towards catalytic properties and thermal stability for CO oxidation are investigated. The thickness of nickel oxide coating layer was controlled accurately by varying the ALD cycles. Characterizations including TEM, XPS, FTIR and XAFS were undertaken to explore the origin of the CO oxidation catalytic activity enhancement. In-situ AFM test is carried out to explore the mechanism of nanoparticles migration and sintering phenomenon in different environment by controlling the calcination temperature and oxygen partial pressure. Nickel oxide anchors Pt NPs with a strong metal oxide interaction, and coating structure around Pt NPs provide physical blocking that suppresses NP particle migration and coalescence. The catalysts show both enhanced CO conversion activity and improved sintering resistance up to 700 °C under oxidative atmospheric conditions.