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利用流动电解池与电化学原位红外光谱技术研究了温度和阴离子竞争吸附等因素对室温下Pt电极上COad的脱附机理与动力学的影响.研究表明当溶液中有Cl-或硫酸根等离子时,室温下未观察到COad从电极表面脱附.但是当溶液相存在与COad的吸附能相当甚至比之更大的粒子如CO或CN-时,COad可以被取代而从电极表面脱附.红外光谱表明吸、脱附过程中CN-ad与COad的红外谱带强度存在反线性的关系,而且变温实验估算得到COad的脱附能垒小于40kJmol-1,该脱附能垒远比CO的吸附能(>60kJmol-1)小.上述结果进一步验证了室温下COad在Pt电极上的脱附不是热激发脱附.据此结果,本文详细地讨论了我们早先提出的吸附驱动的脱附机理的历程与能量来源.
The effect of temperature and anion competitive adsorption on the desorption mechanism and kinetics of COad on Pt electrode at room temperature was investigated by using mobile electrolytic cell and electrochemical in-situ infrared spectroscopy. The results show that when the solution contains Cl- or sulfate ions , No COad desorption from the electrode surface was observed at room temperature, but COad could be displaced to desorb from the electrode surface when there is a particle in the solution phase that has a comparable or even larger adsorption energy to COad, such as CO or CN-. The IR spectra showed that there was an inverse linear relationship between the IR band intensities of CN-ad and COad in the adsorption and desorption processes. Moreover, the desorption energy barrier of COad was estimated to be less than 40 kJmol-1 by temperature-programmed experiments. (> 60kJmol-1) .The above results further verify that the desorption of COad on the Pt electrode at room temperature is not by thermal excitation and desorption. Based on the results, we discussed in detail the adsorption-driven desorption mechanism we proposed earlier The course and energy source.