Unique Dynamics of Water Confined on the Surface of Metal Oxide Clusters |
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| Authors: | Linkun Cai Yuyan Lai Prof. Dr. Panchao Yin |
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| Affiliation: | South China Advanced Institute for Soft Matter Science and Technology, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510641 P. R. China |
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| Abstract: | Water confined on metal oxide surface plays significant roles in heterogeneous catalysis. Heteropolyacid, a 1.2 nm-metal oxide cluster with well-defined structure, is applied as a model to understand the dynamics of water on its surface. The surface water strongly associates with heteropolyacid cluster and form the so-called ‘pseudoliquid phase’ where catalytic reactions are conducted. Broadband dielectric spectroscopy and differential scanning calorimetry have been applied to probe the dynamics of water in this pseudoliquid phase. A supercooling phase transition of water below its normal melting temperature and a dipolar glassy relaxation behaviour due to the hindered dynamics of water have been observed. The rich dynamic behavior on the surface of such well-defined metal clusters provide new perspectives to understand the properties of surface water and their relation to catalytic performance of heteropolyacid. |
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| Keywords: | confinement dipolar glassy relaxation heteropolyacid pseudoliquid phase water dynamics |
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