Pt电极表面共吸附层NO和CO氧化还原的CV及原位FTIR研究  

Cyclic voltammetric and in situ FTIR spectroscopic studies of redox of nitric oxide and carbon monoxide coadlayers on Pt electrode

作　　者：程前[1,2] 姜艳霞[2] 孙世刚[2] 

机构地区：[1]厦门理工学院环境工程系,厦门361024 [2]固体表面物理化学国家重点实验室厦门大学化学化工学院化学系,厦门361005

出　　处：《中国科学：化学》2011年第9期1482-1488,共7页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(20833005,20873116,20620130427 & 60936003)资助

摘　　要：应用电化学循环伏安方法(CV)和原位傅里叶变换红外反射光谱(in situ FTIRS)研究了酸性溶液中Pt多晶电极表面NO和CO的共吸附行为及吸附态CO对吸附物种NO氧化还原反应的影响.研究结果表明,0.20V(vs.SCE)时,CO和NO能同时稳定吸附在Pt电极表面,CO以线性吸附态(COL)存在,NO以桥式吸附态(NOB)和线性吸附态(NOL)共存.COL的共存使得NO的还原电流峰电位负移约0.024V,并且促使不易被氧化的NOB在0.93V处被氧化.原位FTIRS研究进一步表明,NO可以置换预吸附在电极表面的CO,NO和CO在Pt多晶电极表面的吸附是一个竞争吸附的过程.在0.45V～1.2V电位区间,NO和CO都能转化为环境友好产物,分别为NO3-和CO2.且Pt电极表面共吸附物种CO的量直接影响NOB的氧化产物NO3-的生成量.The coadsorption behavior of nitric oxide （NO） and carbon monoxide （CO） on the polycrystalline Pt electrode and the influence of CO on the oxidation-reduction reactions of coadsorbed NO were studied by using cyclic voltammetric （CV） and in situ FTIR spectroscopy in acid media. The results demonstrated that the NO/CO adlayers can be adsorbed on the Pt electrode stably at 0.20 V （vs. SCE）. CO existed with linear adsorption state （COL）, and NO were coadsorded with both bridged adsorption state （NOB） and linear adsorption state （NOL）. Due to the coadsorption of COL, the reduction peak potentials of NO were negatively shifted about 0.024 V, and NOB which should have been not accessible to be oxidized were oxidized at 0.93 V. In situ FTIRS further indicated that NO can replace CO which is pre-adsorbed on the Pt electrode, and it is a competitive adsorption process between NO and CO. Both NO and CO can be converted into environmentfriendly species, which are NO3- and CO2 respectively. The quantity of NO3- depends on the adsorption quantity of CO on the Pt electrode.

关 键 词：一氧化氮 一氧化碳 共吸附 Pt多晶电极 环境友好产物 

分 类 号：O643.3[理学—物理化学]