Acetic Acid Adsorption on Anatase TiO2(101)
Acetic Acid Adsorption on Anatase TiO2(101)
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DOI：
10.1021/jp303514g
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发表时间：
2012-05-31
影响因子：
3.7
通讯作者：
Thornton, Geoff
中科院分区：
文献类型：
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作者：
Grinter, David C.;Nicotra, Marco;Thornton, Geoff
用扫描隧道显微镜（STM）研究了乙酸在TiO 2（101）表面的吸附和反应活性。在低覆盖率下，观察到乙酸在STM中具有与解离双齿结合几何形状一致的特征外观。在室温下，乙酸与Cu（101）表面有较强的相互作用，粘附概率接近1。当在升高的温度（420 K）下沉积时，饱和覆盖率显示出部分有序的超结构，具有两个域跨小区域的表面。发现这些结构域的周期性为（2 X 1），再次与乙酸酯沿[010]方向沿着与两个相邻Ti-5c位点的双齿结合几何结构一致。加热的乙酸盐覆盖的表面，以570 K在真空中导致清洁解吸类似于90%的分子，只留下一小部分未解吸的，主要是位于台阶边缘的结晶。还发现+6 V的STM尖端脉冲从表面解吸乙酸分子。
The adsorption and reactivity of acetic acid on anatase TiO2(101) has been investigated with scanning tunneling microscopy (STM). At low coverage, acetic acid is observed to have a characteristic appearance in STM consistent with a dissociative bidentate binding geometry. At room temperature acetic acid has a relatively strong interaction with the anatase (101) surface and a near-unity sticking probability. When deposited at elevated temperatures (420 K), a saturated coverage displays a partially ordered superstructure with two domains across small regions of the anatase surface. The periodicity of these domains was found to be (2 X 1), again consistent with a bidentate binding geometry of the acetate to two neighboring Ti-5c sites along the [010] direction. Heating the acetate-covered surface to 570 K in ultrahigh vacuum resulted in clean desorption of similar to 90% of the molecules, leaving only a small fraction undesorbed that were mainly situated at the step edges of the anatase. STM tip pulsing of +6 V was also found to desorb acetate molecules from the surface.