Atomically dispersed copper species on ceria for the low-temperature water-gas shift reaction

• 作者: Jing Ning Yan Zhou Wenjie Shen
• 来源期刊: 中国科学：化学（英文版）
• 年，卷（期）: 2021,（7）
• 所属期刊栏目: ARTICLES
• 页码范围: 1103-1110
• 页数: 8页
• 语种: 英文

摘要

The structure of copper species,dispersed on nanostructured ceria(particles,rods and cubes),was analyzed by scanning transmission electron microscopy(STEM)and X-ray photoelectron spectroscopy(XPS).It was interestingly found that the density of surface oxygen vacancies(or defect sites),induced by the shape of ceria,determined the geometrical structure and the chemical state of copper species.Atomically dispersed species and monolayers containing few to tens of atoms were formed on ceria particles and rods owing to the enriched anchoring sites,but copper clusters/particles co-existed,together with the highly dispersed atoms and monolayers,on cubic ceria.The atomically dispersed copper sites and monolayers interacted strongly with ceria,involving a remarkable charge transfer from copper to ceria at their interfaces.The activity for the low-temperature water-gas shift reaction of the Cu/CeO2 catalysts was associated with the fraction of the positively-charged copper atoms,demon-strating that the active sites could be tuned by dispersing Cu species on shape-controlled ceria particles.