摘要
应用红外光谱技术研究了CO,CO_2等在氧化态和还原态CeO_2上表面吸附体的形成及反应,归属了所观察到的红外吸收带,证实在表面上存在HCO_3^-,HCOO^-,及两种不同键合方式的CO_3^(2-)等表面物种。观察到HCO_3^-有两种存在形式,一种在较高的温度下稳定,一种在较低温度下稳定。在不同温度下HCOO^-、CO_3^(2-)、HCO_3^-三种表面物种之间可相互转化,在氧化态样品上,CO最终氧化生成CO_2气体。
The formation and reaction of surface species of CO and CO_2 adsorptionon oxidized and reduced CeO_2 amples were studied by infrared spectroscopy.The bands obtained were assigned. The HCO_3^-, HCOO^- and CO_3~2-) speciesexisted on the surface of samples. Two forms of HCO_3^- species were detected,one was stable at low emperature, the other was stable at high temperature.HCO_3^-, CO_3^(2-) and HCOO^- species could transform each ther at differenttemperature. It was observed that CO was oxidized to produce CO_2 gas on theoxidized sample.
关键词
氧化铈
一氧化碳
二氧化碳
吸附
surface adsorption species
CO adsorption
CO_2 adsorption
surface infrared spectroscopy
