In situ x-ray spectroscopy unveils charge-driven CO oxidation over Cu-TiO2 mesospheres
學年 114
學期 1
出版（發表）日期 2025-11-18
作品名稱 In situ x-ray spectroscopy unveils charge-driven CO oxidation over Cu-TiO2 mesospheres
作品名稱（其他語言）
著者 Thanigai Arul Kumaravelu; Xian-Teng Yu; Hsiao-Tsu Wang; Jian Wang; Sofia Ya Hsuan Liou; Li Cheng Kao; Wen-Ta Yang; Chen-Jie Yang; Ying-Rui Lu; Chi-Liang Chen; Bi-Hsuan Lin; Da-Hua Wei; Chung-Li Dong
單位
出版者
著錄名稱、卷期、頁數 ACS Sustainable Chemistry & Engineering 13(47), p.20451-20463
摘要 Carbon monoxide (CO), a hazardous byproduct of incomplete hydrocarbon combustion, poses significant environmental and health concerns. Efficient and low-temperature catalytic oxidation of CO to CO2 remains a key challenge. In this study, Cu-doped TiO2 nanostructures with varying Cu contents (0–20 wt %) were synthesized via a one-step aerosol-assisted self-assembly (AASA) method. X-ray diffraction confirmed the anatase TiO2 phase, and Brunauer–Emmett–Teller (BET) analysis revealed an increased pore size at higher Cu loadings. The 20 wt % Cu-TiO2 (20CTO) sample exhibited superior CO oxidation performance, initiating conversion at ∼90 °C. Synchrotron X-ray fluorescence mapping showed more uniform Cu dispersion in 20CTO than in 10CTO. Site-dependent charge dynamics of Cu observed at lower dopings (5CTO, 10CTO) diminished in 20CTO. X-ray absorption near edge structure (XANES) revealed a higher Cu oxidation state (>2+) and a reduced unoccupied density of Ti states in 20CTO, indicating charge transfer from Cu to Ti. Extended X-ray absorption fine structure (EXAFS) analyses showed altered Cu–O and Ti–O coordination at higher Cu loading. In site XANES revealed that Cu’s unoccupied states decreased with increasing temperature, while Ti exhibited increased octahedral symmetry and unoccupied states. Spectromicroscopic analysis confirmed spatially heterogeneous distributions of Ti4+ and Cu2+ states in 20CTO. These findings underscore the role of Cu doping in modulating the local electronic structure and promoting low-temperature CO oxidation.
關鍵字 CO to CO2 conversion; XANES; EXAFS; X-ray mapping; STXM
語言 en
ISSN 2168-0485
期刊性質 國外
收錄於 SCI
產學合作
通訊作者
審稿制度 是
國別 USA
公開徵稿
出版型式 ,電子版