Grain boundary boosting the thermal stability of Pt/CeO_(2)thin films  

作　　者：Luyao Wang Xiaobao Li Xiangchen Hu Shuyue Chen Zhehao Qiu Yifan Wang Hui Zhang Yi Yu Bo Yang Yong Yang Pasquale Orgiani Carmela Aruta Nan Yang 

机构地区：[1]Electrochemical thin film group,School of physical science and technology,ShanghaiTech University,Shanghai 201210,China [2]State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China [3]School of physical science and technology,ShanghaiTech University,Shanghai 201210,China [4]CNR-IOM,TASC National Laboratory,I-34149 Trieste,Italy [5]CNR-SPIN,UOS Roma,Area della Ricerca di Tor Vergata,Rome I-00133,Italy

出　　处：《Nano Research》2023年第2期3278-3286,共9页纳米研究（英文版）

基　　金：The APXPS experiments were performed at BL02B01 of SSRF with the approval of the Proposal Assessing Committee of SiP.ME2 platform project(Proposal No.2019-SSRF-PT-011613);the Natural Science Foundation of China(No.11227902);the Shanghai Key Research Program(No.20ZR1436700).

摘　　要：Understanding how defect chemistry of oxide material influences the thermal stability of noble metal dopant ions plays an important role in designing high-performance heterogeneous catalytic systems.Here we use in-situ ambient-pressure X-ray photoemission spectroscopy(APXPS)to experimentally determine the role of grain boundary in the thermal stability of platinum doped cerium oxide(Pt/CeO_(2)).The grain boundaries were introduced in Pt/CeO_(2)thin films by pulsed laser deposition without significantly change of the surface microstructure.The defect level was tuned by the strain field obtained using a highly/low mismatched substrate.The Pt/CeO_(2)thin film models having well defined crystallographic properties but different grain boundary structural defect levels provide an ideal platform for exploring the evolution of Pt–O–Ce bond with changing the temperature in reducing conditions.We have direct demonstration and explanation of the role of Ce^(3+)induced by grain boundaries in enhancing Pt2+stability.We observe that the Pt^(2+)–O–Ce^(3+)bond provides an ideal coordinated site for anchoring of Pt^(2+)ions and limits the further formation of oxygen vacancies during the reduction with H_(2).Our findings demonstrate the importance of grain boundary in the atomic-scale design of thermally stable catalytic active sites.

关 键 词：platinum doped cerium oxide(Pt/CeO_(2)) pulsed laser deposition epitaxial thin films grain boundaries defect engineering in-situ ambient-pressure X-ray photoemission spectroscopy 

分 类 号：TB34[一般工业技术—材料科学与工程]