Mechanism of Sulfur Poisoning and Storage: Adsorption and Reaction of SO2 with Stoichiometric and Reduced Ceria Films on Cu(111)
Mechanism of Sulfur Poisoning and Storage: Adsorption and Reaction of SO2 with Stoichiometric and Reduced Ceria Films on Cu(111)
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DOI：
10.1021/jp207014z
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发表时间：
2011-09
影响因子：
3.7
通讯作者：
M. Happel;Y. Lykhach;N. Tsud;T. Skála;K. Prince;V. Matolín;J. Libuda
中科院分区：
文献类型：
--
作者：
M. Happel;Y. Lykhach;N. Tsud;T. Skála;K. Prince;V. Matolín;J. Libuda
利用同步辐射光电子能谱（SR-PES）研究了SO_2与化学计量比CeO_2（111）和还原态CeO_2-x/Cu（111）薄膜的相互作用。利用共振光电子能谱（RPES）监测铈氧化态的变化。SO2在150和300 K下的吸附主要导致在还原和化学计量的氧化铈上形成亚硫酸盐（SO 32-）物种。其他物种，如硫酸盐（SO 42-），SO2化学吸附在阳离子位点，阴离子SO2-，原子硫，表面硫化物，和散装氧硫化物检测。这些物种的起源进行了讨论有关的氧化铈阳离子在表面的氧化态的变化。在150和300 K的吸附后形成的物种的热演化进行了系统的研究化学计量和减少的薄膜。结果表明，亚硫酸盐部分解吸释放SO2，部分分解。在一般情况下，还原CeO 2-x表面被发现是多个。
We have performed a systematic synchrotron radiation photoelectron spectroscopy (SR-PES) study of the interaction of SO2 with stoichiometric CeO2(111) and reduced CeO2–x films supported on Cu(111). Resonant photoelectron spectroscopy (RPES) was utilized to monitor changes in the cerium oxidation states. Adsorption of SO2 at 150 and 300 K results mostly in formation of sulfite (SO32–) species on both reduced and stoichiometric ceria. Other species such as sulfate (SO42–), SO2 chemisorbed at cationic sites, anionic SO2–, atomic sulfur, surface sulfides, and bulk oxy-sulfides were detected. The origin of these species is discussed in relation to the changes in the oxidation state of ceria cations at the surface. The thermal evolution of the species formed upon adsorption at 150 and 300 K was studied systematically on both the stoichiometric and the reduced films. It was found that the sulfite partially desorbs to release SO2 and partially decomposes. In general, the reduced CeO2–x surface was found to be muc...