CO-Induced Smoluchowski Ripening of Pt Cluster Arrays on the Graphene/Ir(111) Moir茅
详细信息 查看全文
- 作者：Timm Gerber ; Jan Knudsen ; Peter J. Feibelman ; Elin Gr氓n盲s ; Patrick Stratmann ; Karina Schulte ; Jesper N. Andersen ; Thomas Michely
- 刊名：ACS Nano
- 出版年：2013
- 出版时间：March 26, 2013
- 年：2013
- 卷：7
- 期：3
- 页码：2020-2031
- 全文大小：860K
- 年卷期：v.7,no.3(March 26, 2013)
- ISSN：1936-086X
文摘
Regular Pt cluster arrays grown on the moir茅 template formed by graphene on Ir(111) were tested for their stability with respect to CO gas exposure. Cluster stability and adsorption-induced processes were analyzed as a function of cluster size, with in situ scanning tunneling microscopy and X-ray photoelectron spectroscopy. Small clusters containing fewer than 10 atoms were unstable upon CO adsorption. They sintered through Smoluchowski ripening鈥攃luster diffusion and coalescence鈥攔ather than the frequently reported Ostwald ripening mediated by metal鈥揳dsorbate complexes. Larger clusters remained immobile upon CO adsorption but became more three-dimensional. Careful analysis of the experimental data complemented by ab initio density functional theory calculations provides insight into the origin of the CO-induced Pt cluster ripening and shape transformations.