文献类型：期刊文献

英文题名：Catalytic Activities of Low-Coordinated Ce for Methane Conversion

作者：Zhou, Hui[1,2,3];Wu, Xin-Ping[1,2,3];Gong, Xue-Qing[1,2,3]

机构：[1]East China Univ Sci & Technol, Key Lab Adv Mat, Sch Chem & Mol Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Joint Int Res Lab Precis Chem & Mol Engn, Sch Chem & Mol Engn, Feringa Nobel Prize Scientist Joint Res Ctr,Ctr C, 130 Meilong Rd, Shanghai 200237, Peoples R China;[3]East China Univ Sci & Technol, Res Inst Ind Catalysis, Sch Chem & Mol Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2022

卷号：14

期号：3

外文期刊名：CHEMCATCHEM

收录：;EI(收录号：20215211374070);WOS:【SCI-EXPANDED(收录号:WOS:000731968600001)】；

基金：This work was supported by National Key R&D Program of China (2018YFA0208602, 2021YFB3500700) and National Natural Science Foundation of China (21825301, 22003016, 92045303, 92145302).

语种：英文

外文关键词：CeO2; low-coordinated Ce; Ca doping; selective oxidation of CH4; density functional theory calculations

摘要：In heterogeneous catalysis, the catalytic activity of an active center strongly correlates with its coordination number. In this work, density functional theory calculations corrected by on-site Coulomb interactions were conducted to investigate the catalytic performances of the CeO4-terminated reconstructed CeO2(100) (CeO4-t) and the Ca-doped CeO4-t surfaces. The undoped CeO4-t surface contains single 4-fold coordinated Ce (Ce-4c) sites on its top surface layer, and the Ca-doped CeO4-t surface can expose even lower-coordinated 3-fold Ce (Ce-3c) sites. We found that the empty 4f states of the single Ce-3c sites on the Ca-doped CeO4-t surface have much lower energies than that of the single Ce-4c sites on the undoped CeO4-t surface, which can effectively boost the reduction of Ce4+ to Ce3+. We further studied the selective oxidation of CH4 to CH3OH on the two surfaces and found that the isolated nature combined with the strong electron-reservoir character of the single Ce-3c site makes it highly desirable for the selective activation of the first C-H bond of CH4, while the subsequent C-H bond cleavage step is less affected by such low-coordinated Ce and the CH3OH formation becomes more facile on the Ca-doped CeO4-t surface, giving rise to the high activity and selectivity of the Ca-doped CeO4-t surface toward the selective oxidation of CH4 to CH3OH.