Ripening-resistance of Pd on TiO 2 (110) from first-principles kinetics
- PDF / 676,076 Bytes
- 9 Pages / 595.276 x 785.197 pts Page_size
- 33 Downloads / 129 Views
RESEARCH ARTICLE
Ripening-resistance of Pd on TiO2(110) from first-principles kinetics Qixin WAN1,2, Hao LIN3,4, Shuai WANG1, Jiangnan DAI (✉)1, Changqing CHEN1 1 Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China 2 Key Laboratory for Optoelectronics and Communication of Jiangxi Province, Jiangxi Science and Technology Normal University, Nanchang 330013, China 3 State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 110623, China 4 University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China
© Higher Education Press and Springer-Verlag GmbH Germany, part of Springer Nature 2019
Abstract Suppressing sintering of supported particles is of importance for the study and application of metal-TiO2 system. Theoretical study of Ostwald ripening of TiO2(110)-supported Pd particles would be helpful to extend the understanding of the sintering. In this paper, based on density functional theory (DFT), the surface energy of Pd and the total activation energy (the sum of formation energy and diffusion barrier) of TiO2-supported Pd were calculated. Since the total activation energy is mainly contributed from the formation energy, it is indicated that the ripening of Pd particles would be in the interface control limit. Subsequently, the calculated surface energy and total activation energy were used to simulate Ostwald ripening of TiO2(110)-supported Pd particles. As a result, in comparison with larger particles, smaller particles would worsen the performance of ripening-resistance according to its lower onset temperature and shorter half-life time. The differences on ripeningresistance among different size particles could be mitigated along with the increase of temperature. Moreover, it is verified that the monodispersity can improve ripening resistance especially for the smaller particles. However, the different performances of the ripening originating from difference of the relative standard deviation are more obvious at higher temperature than lower temperature. This temperature effect for the relative standard deviation is the inverse of that for the initial main particle size. It is indicated that the influence of dispersity of TiO2(110)supported Pd particles on ripening may be more sensitive at higher temperature. In this contribution, we extend the Received April 24, 2019; accepted June 17, 2019 E-mail: [email protected]
first principle kinetics to elaborate the ripening of Pd on TiO2(110). It is expected that the information from first principle kinetics would be helpful to the study in experiments. Keywords TiO2(110)
1
first-principles, Ostwald ripening, Pd,
Introduction
The surface properties of metal oxides have attracted great attention for years. Especially, TiO2 has been studied intensively owing to its wide-ranging applications such as photocatalysis, energy storage, fuel cells and pollution abatement [1–9]. In catalysis, despite the fact that TiO2 is not
Data Loading...
