Gao, Y (reprint author), Chinese Acad Sci, Shanghai Inst Appl Phys, Div Interfacial Water, Shanghai 201800, Peoples R China.
; Gao, Y (reprint author), Chinese Acad Sci, Shanghai Inst Appl Phys, Key Lab Interfacial Phys & Technol, Shanghai 201800, Peoples R China.
; Gao, Y (reprint author), Chinese Acad Sci, Shanghai Sci Res Ctr, Shanghai 201204, Peoples R China.
文章类型:
期刊文献
英文摘要:
The structures of the metal nanoparticles are crucial for their catalytic activities. How to understand and even control the shape evolution of nanoparticles under reaction condition is a big challenge in heterogeneous catalysis. It has been proved that many reactive gases hold the capability of changing the structures and properties of metal nano particles. One interesting question is whether water vapor, such a ubiquitous environment, could induce the shape evolution of metal nanoparticles. So far this question has not received enough attention yet. In this work, we developed a model based on the density functional theory, the Wulff construction, and the Langmuir adsorption isotherm to explore the shape of metal nanoparticle at given temperature and water vapor pressure. By this model, we show clearly that water vapor could notably increase the fraction of (110) facets and decrease that of (111) facets for 3-8 nm Cu nanoparticles, which is perfectly consistent with the experimental observations. Further investigations indicate the water vapor has different effects on the different metal species (Cu, Au, Pt, and Pd). This work not only helps to understand the water vapor effect on the structures of metal nanoparticles but also proposes a simple but effective model to predict the shape of nanoparticles in certain environment.
