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论文类型：期刊论文

发表时间：2012-11-01

发表刊物：COMPUTATIONAL AND THEORETICAL CHEMISTRY

收录刊物：SCIE、Scopus

卷号：999

页面范围：246-250

ISSN号：2210-271X

关键字：AumPdn clusters; DFT; Au:Pd ratio; Size effects; Electronic properties

摘要：The geometry and stability of the AumPdn bimetallic cluster have been studied using density functional theory with the GGA-PW91 exchange-correlation functional. A series of AumPdn (N = 38, 55, 79, N=m + n, m/n approximate to 2:1 and 5:1) bimetallic clusters with truncated octahedral shape was used to model such bimetallic nanosystems. The excess energy of two ratios configurations demonstrates that the m/n approximate to 2:1 ratio of AumPdn clusters is more stable than the m/n approximate to 5:1 ratio. The excess energy order of AumPdn clusters with the m/n approximate to 2:1 ratio is Au24Pd14 > Au52Pd27 > Au36Pd19. which shows a complicated size dependency. The Au24Pd14 cluster for N = 38 is the most stable bimetallic geometry. Hirshfeld charges and electron density difference show that the charge transfers from the Pd atoms to the Au atoms associated with the ionic feature of Au-Pd bonds. The PDOS, IP and EA show the sensitivity to Au:Pd ratio and cluster size N of AumPdn clusters. Such nanocrystallites are expected to exhibit peculiar catalytic properties and should be prone to retaining their initial shape under catalytic conditions due to the thermodynamically stability. (C) 2012 Elsevier B.V. All rights reserved.