Efficient Catalytic Decomposition of CO2 to CO and O2 over Pd/Mixed-Conducting Oxide Catalyst in an Oxygen-Permeable Membrane Reactor

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• 作者：Wanqin Jin ; Chun Zhang ; Xianfeng Chang ; Yiqun Fan ; Weihong Xing ; Nanping Xu
• 刊名：Environmental Science & Technology
• 出版年：2008
• 出版时间：April 15, 2008
• 年：2008
• 卷：42
• 期：8
• 页码：3064 - 3068
• 全文大小：376K
• 年卷期：v.42,no.8(April 15, 2008)
• ISSN：1520-5851

文摘

The thermal decomposition of CO₂ to CO and O₂ is a potential route for the consumption and utilization of CO₂. However, this reaction is limited by both the thermodynamic equilibrium and the kinetic barrier. In this study, we reported an innovative catalytic process to decompose CO₂ in an oxygen-permeation membrane reactor packed with a mixed-conducting oxide supported noble metal catalyst, or Pd/SrCo_0.4Fe_0.5Zr_0.1O_3−δ (Pd/SCFZ), which is of high activity in the decomposition of CO₂ into CO and O₂. Pd/SCFZ catalyst was prepared by incipient wetness impregnation of the SCFZ powders with an aqueous solution of PdCl₂, and the CO₂ sorption/desorption property was examined by in situ Fourier transform infrared spectroscopy and temperature-programmed desorption-mass spectrometry technologies. It was shown that there appeared a typical of bridged carbonyls (Pd-CO) on the surface of the Pd/SCFZ catalyst formed after CO₂ decomposition. Both CO₂ and CO could be detected in the species desorbed from Pd/SCFZ catalyst, which implied that the Pd/SCFZ catalyst could effectively activate the CO₂ molecule. During the catalytic process, furthermore, the activity of the Pd/SCFZ catalyst can self-regenerate by removing the produced lattice oxygen through the dense oxygen-permeable ceramic membrane. At 900 °C, this catalytic process attains 100% of CO formation selectivity at 15.8% of CO₂ conversions.