Dissociation mechanism of methanol on a Si(111)-(7x7) surface studied by scanning tunneling microscopy

CORC > 厦门大学 > 化学化工－已发表论文

	Dissociation mechanism of methanol on a Si(111)-(7x7) surface studied by scanning tunneling microscopy
	Xie, Z. X. ; Uematsu, Y. ; Lu, X. ; Tanaka, K. ; Lv X(吕鑫)
刊名	http://dx.doi.org/10.1103/PhysRevB.66.125306
	2002-09-15
关键词	SYNCHROTRON-RADIATION PHOTOEMISSION SI(111)7X7 SURFACE POROUS SILICON CORE-LEVEL ADSORPTION ETHANOL METHOXY WATER
英文摘要	Adsorption of methanol on a Si(111)-7x7 surface was studied by means of scanning tunneling microscopy (STM). The STM image of adatoms and the tunneling spectroscopy at the rest atom position suggest that the CH3OH molecule dissociates on an adatom and rest atom pair by forming Si-OCH3 and Si-H, respectively. At saturation, half of the adatoms, three adatoms, and all three rest atoms are changed to Si-OCH3 and Si-H in every half unit cell. When the adatom changes to Si-OCH3, the Si adatom becomes invisible at the bias potential of 2.0 V. In contrast, Si-OCH3 and the intact adatom have equal image intensity at 3.0 V, although center adatoms are brighter than corner adatoms. As a result, the saturated surface shows a characteristic uniform pattern at 3.0 V, although half of the adatoms are Si-OCH3 and the other half are intact Si adatoms. By counting darkened corner and center adatoms at the bias of 2.0 V, the site-dependent kinetics for the adsorption of CH3OH was established. The sticking probability for the formation of Si-OCH3 and Si-H was independent of the coverage, and the number of Si-OCH3 in each half unit cell is consecutively increased in a sequence of 1, 2, and 3 with increasing exposure. These facts indicate that the dissociation of CH3OH is accomplished via a precursor state in each half unit cell: that is, each half unit cell works independently as if it were a molecule.
语种	英语
内容类型	期刊论文
源URL	[http://dspace.xmu.edu.cn/handle/2288/61409]
专题	化学化工－已发表论文
推荐引用方式 GB/T 7714	Xie, Z. X.,Uematsu, Y.,Lu, X.,et al. Dissociation mechanism of methanol on a Si(111)-(7x7) surface studied by scanning tunneling microscopy[J]. http://dx.doi.org/10.1103/PhysRevB.66.125306,2002.
APA	Xie, Z. X.,Uematsu, Y.,Lu, X.,Tanaka, K.,&吕鑫.(2002).Dissociation mechanism of methanol on a Si(111)-(7x7) surface studied by scanning tunneling microscopy.http://dx.doi.org/10.1103/PhysRevB.66.125306.
MLA	Xie, Z. X.,et al."Dissociation mechanism of methanol on a Si(111)-(7x7) surface studied by scanning tunneling microscopy".http://dx.doi.org/10.1103/PhysRevB.66.125306 (2002).