限域Pd纳米微粒的增强红外吸收及其对电位响应速度的原位分子探针红外反射光谱研究

In situ FTIR Reflection Spectroscopy of Molecule Probe Studies of Enhanced IR Adsorbtion and Response Rate to Potential on Pd Nanoparticles Confined

Y型沸石分子筛的超笼为微反应器 ,以“瓶中造船”方式合成纳米钯粒子 (nm Pd)。分别以聚氯乙烯(PVC)和Nafion(高氟化树脂 )为粘合剂 ,采用混合滴涂法和分步滴涂法制备载钯分子筛修饰电极。以CO为探针 ,用电化学原位FTIR反射光谱研究吸附态CO的红外光学性能 ,研究发现采用上述两种方法制备的载钯分子筛修饰电极具有同样的CO增强红外吸收特性和不同的电位响应速度 ,表明CO增强红外吸收特性只与钯的纳米尺度有关 ,而分子筛修饰电极的电位响应速度和电子传输能力除与分子筛本身的结构有关外 ,还受粘合剂影响。

Palladium nanoparticles (nm-Pd) were synthesized in the supercages of Y-zeolite via 'ship-in-a-bottle'. Polyvinyl chloride (PVC) and Nafion were used as bonds respectively to prepare zeolite-modified electrode loading nm-Pd by mixed coat and steped coat. IR optical properties of adsorbed CO (CO(ad)) were studied by in situ electrochemical FTIR spectrum on zeolite-modified electrode surface prepared by different bond and coating method. Results display the same enhanced IR absorption of CO(ad) and different response rate to potential as well as the ability of electron transfer on PVC and Nafion film. Time-dependent nu(infinityB) shift was studied for obtaining the information of response rate to potential and electron transfer ability of PVC and Nafion coating. A larger potential lag on PVC coating electrode and a very small potential lag on Nafion coating film were found, showing that different bond and prepared method affect response rate to potential of zeolite-modified electrode. These findings are significant in understanding special optical performance and the electron transfer mechanism of zeolite-modified electrode.