Yee Nelson C, Chottiner Gary S, Scherson Daniel A
J Phys Chem B. 2005 Apr 28;109(16):7610-3. doi: 10.1021/jp050947t.
Changes in the properties of CO adsorbed at saturation coverages on Pt(100) induced by subsequent coadsorption of fixed amounts of D2O at 105 K in ultrahigh vacuum (UHV) were monitored by time-resolved infrared reflection absorption spectroscopy (tr-IRAS). The linear- and bridge-bonded CO stretching features were found to change in intensity and shift toward lower energies as a function of time at fixed CO and D2O coverages. Also observed was the development of multiple features in both CO spectral regions depending on the amount of D2O on the surface. These findings indicate that, under the conditions of these experiments, the interfacial dynamics are relatively slow, on the order of minutes, involving a gradual rearrangement of adsorbed CO and D2O on the surface to yield surface solvated CO, as has been suggested in the literature (Kizhakevariam et al. J. Chem. Phys. 1994, 100, 6750). This factor should be considered when comparing, quantitatively, shifts induced by water coadsorption with CO on Pt single crystals in UHV with CO adsorption on the same surfaces in electrochemical environments.
通过时间分辨红外反射吸收光谱（tr - IRAS）监测了在超高真空（UHV）中于105 K下固定量的D₂O与CO在Pt(100)上共吸附后，饱和覆盖度下吸附的CO性质的变化。发现在固定的CO和D₂O覆盖度下，线性和桥式键合的CO伸缩特征的强度会随时间变化，并向更低能量方向移动。还观察到，根据表面上D₂O的量，在两个CO光谱区域都会出现多个特征。这些发现表明，在这些实验条件下，界面动力学相对较慢，约为几分钟，涉及表面吸附的CO和D₂O逐渐重新排列以生成表面溶剂化的CO，正如文献（Kizhakevariam等人，《化学物理杂志》，1994年，100卷，6750页）中所提出的那样。在将超高真空下Pt单晶表面上CO与水共吸附引起的位移与相同表面在电化学环境中的CO吸附位移进行定量比较时，应考虑这一因素。
