Effects of non-stoichiometry and dopants in nanocrystalline cerium oxide-based c

2019-05-13 11:52:32

Cu Co activity nanocrystalline oxide

责任者: Tschope, Andreas;Ying, Jackie Y. 单位: Massachusetts Inst of Technology, Cambridge, MA, USA 来源出处: Nanostructured Materials,1995,6(5-8):1005-1008 摘要: Nanocrystalline pure and doped non-stoichiometric CeO2-x were synthesized by inert gas condensation. These materials were investigated as catalyst for redox reactions such as SO2 reduction by CO, and CO oxidation by O2. By controlling the stoichiometry of the oxide catalyst, the effect of bulk oxygen-deficiency on surface catalytic activity was revealed. Nanocrystalline CeO2-x catalysts exhibited high catalytic activity, reversibility, and excellent resistance against deactivation by CO2. Cu-doping of CeO2-x was found to further promote catalytic activity. Nanocrystalline homogeneous Cu-Ce mixed-metal oxide was synthesized by magnetron sputtering from a mixed metal target. Annealing at 650°C resulted in Cu segregation and formation of CuO clusters. Catalytic activity in CO oxidation by O2 was not affected by this annealing treatment. STEM Cu elemental mapping illustrated that although some large CuO clusters were formed in thermal treatments, substantial Cu still remained highly dispersed. 关键词: Catalysts;Nanostructured materials;Redox reactions;Doping (additives);Cerium compounds;Stoichiometry;Chemical variables control;Catalyst activity;Chemical resistance;Annealing;Transmission electron microscopy;Copper oxides;Magnetron sputtering;Reversibility;Cerium oxide