摘要
采用ＸＰＳ等手段对ＬａＣｏＯ３－δ和Ｌａ１－ｘＳｒｘＣｏＯ３－δ纳米粒子进行了表征。结果显示，随ＬａＣｏＯ３－δ纳米粒子粒径的减小，一方面表面钴浓度增加，另一方面，表面ＣｏＯ键的离子性增强和表面氧空位浓度增加。此二者共同导致ＬａＣｏＯ３－δ对一氧化碳氧化的催化活性随其粒径减小而明显增大。ＬａＣｏＯ３－δ纳米粒子中镧被锶部分取代后，其表面结构发生了变化。
Nanometer LaCoO 3-δ and La 1-x Sr xCoO 3-δ with perovskite structure were characterized by XPS technique The results showed that with the decrease of the particle size of LaCoO 3-δ , on one hand, the surface concentration of Co 3+ increesed, on the other hand, the ionicity of surface CoO bond and surface oxygen vocancy concentration increased Both of them enhanced catalytic activity of LaCoO 3-δ for carbon monoxide oxidation with the decrease of its particle size The substitution of strontium for lanthanum in LaCo O 3-δ leaded to the change of its surface structure, which significantly increased its catalytic activity for carbon monoxide oxidation The binding energy of chemical adsorbed oxygen and the ratio of O C A /O C A +O L(O C A : chemical adsorbed oxygen, O L: lattice oxygen on surface) did not depend on the variation of particle size and the substitution of strontium for lanthanum in LaCoO 3-δ
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
1999年第4期309-313,共5页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金资助
内 蒙古教育厅重点研究领域
