| AVS 64th International Symposium & Exhibition | |
| Fundamental Discoveries in Heterogeneous Catalysis Focus Topic | Thursday Sessions |
| Session HC+SS-ThA |
| Session: | Combined Experimental and Theoretical Explorations of the Dynamics of Heterogeneously Catalyzed Reactions |
| Presenter: | Xiao Liu, Huazhong University of Science and Technology, China |
| Authors: | X. Liu, Huazhong University of Science and Technology, China J.M. Cai, Huazhong University of Science and Technology, China B. Shan, Huazhong University of Science and Technology, China R. Chen, Huazhong University of Science and Technology, China |
| Correspondent: | Click to Email |
Platinum (Pt) catalysts have been widely utilized in catalysis due to their excellent catalytic activity, such as CO oxidation, water-shift gas reaction and preferential CO oxidation in hydrogen. As the high cost and large demand of Pt, the improvement of its catalytic efficiency has attracted great attention to reduce its loading. Since catalytic reactions usually happen on surface, the decreasing of Pt catalyst’s size to increase the fraction of exposed atoms is a widely accepted strategy to try to utilize each Pt atom. However, the low temperature activities of the Pt sub-nanometer clusters and single atoms have been greatly limited due to the seriously CO poison effect, which prevents the supplying of active oxygen. Therefore, searching new approaches to supply active oxygen atoms at low temperature is important to enhance the activity and efficiency of Pt catalysts. In this work, the density functional theory (DFT) calculations shows that the designed Pt cluster supported on SmMn2O5 mullite structure exhibits high activity for O2 dissociation than pure SmMn2O5 surface. Inspired by the theoretical results, we have prepared uniform and high dispersed sub-nanometer Pt clusters on SmMn2O5 supports (Ptn/SmMn2O5) via atomic layer deposition method. The interfacial structure of Ptn/SmMn2O5 characterized by high-resolution transmission electron microscopy agrees well with our designed model. The as-prepared Ptn/SmMn2O5 catalyst has shown outstanding room temperature CO oxidation activity and low apparent activation energy, which could result from the strong interfacial interactions as indicated by the X-ray photoelectron spectra and X-ray absorption fine structure results. The in-situ diffuse reflectance infrared Fourier transform spectroscopy, 18O isotope-labelling experiments and DFT calculations shows that the active oxygen supplied by the SmMn2O5 surface is critical to the room temperature CO oxidation activity.