文献类型：期刊文献

英文题名：Unique catalytic mechanisms of methanol dehydrogenation at Pd-doped ceria: A DFT+U study

作者：Chen, Lu[1]; Wu, Xin-Ping[1]; Gong, Xue-Qing[1]

机构：[1] Key Lab. for Adv. Mat. and Jt. Intl. Res. Lab. for Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Centre for Computational Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, China

年份：2022

卷号：156

期号：13

外文期刊名：Journal of Chemical Physics

收录：EI(收录号：20221712039921)

语种：英文

外文关键词：Surface reactions - Chemical bonds - Methanol - Physicochemical properties - Palladium - Dehydrogenation - Density functional theory

摘要：Pd-doped ceria is highly active in promoting oxidative dehydrogenation (ODH) reactions and also a model single atom catalyst (SAC). By performing density functional theory calculations corrected by on-site Coulomb interactions, we systematically studied the physicochemical properties of the Pd-doped CeO2(111) surface and the catalytic methanol to formaldehyde reaction on the surface. Two different configurations were located for the Pd dopant, and the calculated results showed that doping of Pd will make the surface more active with lower oxygen vacancy formation energies than the pristine CeO2(111). Moreover, two different pathways for the dehydrogenation of CH3OH to HCHO on the Pd-doped CeO2(111) were determined, one of which is the conventional two-step process (stepwise pathway) with the O-H bond of CH3OH being broken first followed by the C-H bond cleavage, while the other is a novel one-step process (concerted pathway) involving the two H being dissociated from CH3OH simultaneously even with a lower energy barrier than the stepwise one. With electronic and structural analyses, we showed that the direct reduction of Pd4+ to Pd2+ through the transfer of two electrons can outperform the separated Ce4+ to Ce3+ processes with the help of configurational evolution at the Pd site, which is responsible for the existence of such one-step dehydrogenation process. This novel mechanism may provide an inspiration for constructing ceria-based SAC with unique ODH activities. ? 2022 Author(s).