Open AccessDensity Functional Theory Study on the Nucleation and Growth of Ptn Clusters on γ-Al2O3(001) Surface
Author(s) -
Yue Wang,
Bo Xiang,
Haoxiong Yang,
Changwei Hu
Publication year - 2017
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.7b00342
Subject(s) - nucleation , cluster (spacecraft) , crystallography , dehydrogenation , density functional theory , transition metal , metal , chemical physics , materials science , chemistry , computational chemistry , catalysis , metallurgy , biochemistry , organic chemistry , computer science , programming language
Little is known about the detailed structural information at the interface of Pt n cluster and γ-Al 2 O 3 (001) surface, which plays an important role in the dehydrogenation and cracking of hydrocarbons. Here, the nucleation and growth of Pt n ( n = 1-8, 13) clusters on a γ-Al 2 O 3 (001) surface have been examined using density functional theory. For the most stable configuration Pt n /γ-Al 2 O 3 (001) ( n = 1-8, 13), Pt n clusters bond to the γ-Al 2 O 3 (001) surface through Pt-O and Pt-Al bonds at the expense of electron density of the Pt n cluster. With the increase in the Pt n cluster size, both the metal-support interaction and the nucleation energies exhibit an odd-even oscillation pattern, which are lower for an even Pt n cluster size than those for its adjacent odd ones. Both the metal-surface and metal-metal interactions are competitive, which control the nanoparticle morphology transition from two-dimension (2D) to three-dimension (3D). On the γ-Al 2 O 3 (001) surface, when the metal-support interaction governs, smaller clusters such as Pt 1 , Pt 2 , Pt 3 , and Pt 4 prefer a planar 2D nature. Alternatively, when the metal-metal interaction dominates, larger clusters such as Pt 5 , Pt 6 , Pt 7 , Pt 8 , and Pt 13 exhibit a two-layer structure with one or more Pt atoms on the top layer not interacting directly with the support. Herein, the Pt 4 cluster is the most stable 2D structure; Pt 5 and Pt 6 clusters are the transition from the 2D to the 3D structure; and the Pt 7 cluster is the smallest 3D structure.