摘要
模型催化研究能够更好认识催化过程,指导催化剂的合成.在TiO2(110)单晶上制备了VOx膜,采用俄歇电子能谱(AES)、低能电子衍射(LEED)、高分辨电子能量损失谱(HREELS)考察其结构和物理化学性质,及V-TiO2相互作用和热稳定性.结果表明,真空蒸着法制备的V/TiO2(110)界面发生明显的氧化还原作用,出现了VOx和低价Ti,暴露O2后低价Ti即被氧化回+4价,表面发生重构恢复到(1×1).在O2氛围中制备的VOx/TiO2(110)结构和V的价态会随覆盖度的增加发生变化,利用这种制备方法制备的VOx/TiO2(110)具有较多缺陷位,低温退火(≤600K)可使结构变得更规整.
Model catalyst study can help to understand the catalytic process, guide the synthesis of more e{ficient catalysts. The rood el catalysts comprised of V or vanadia deposited onto TiO2（110） surface was studied. The structure and physical chemistry properties of the VO,/TiO2 （110）, as well as the interaction between V and TiOz and their thermal stability were investigated by high resolution electron energy loss spectroscopy （HREELS）, Auger electron spectrum （AES） and low energy electron diffraction （LEEI））. Oeposi- tion of metallic V onto Ti（）2 （110） surface resulted in charge transfer from V to TiO2 at the interface in which the V atoms were oxi dized and the Ti4＋ cations were reduced; when metallic V deposited was exposed to 02 ,Ti2＋ was oxidized to Ti4 again,and the structure of the surface restored. VOx/TiO2 （110） produced by reactive evaporation under O2 atmosphere at room temperature may possess some defects,which would become a better ordered structure after annealing. The structure and valence of V changed with the increase of the coverage.
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2013年第1期68-74,共7页
Journal of Xiamen University：Natural Science
基金
国家重点基础研究发展计划(973)项目(2010CB732303)
国家自然科学基金项目(20873109,21033006,21073149,20923004)
教育部重大研究计划(309019)
教育部创新研究团队资助项目(IRT1036)
