A crucial role of O2- and O22- on mayenite structure for biomass tar steam reforming over Ni/Ca12Al14O33
A crucial role of O2- and O22- on mayenite structure for biomass tar steam reforming over Ni/Ca12Al14O33
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DOI：
10.1016/j.apcatb.2008.11.004
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发表时间：
2009-05-20
影响因子：
22.1
通讯作者：
Suzuki, Kenzi
中科院分区：
文献类型：
--
作者：
Li, Chunshan;Hirabayashi, Daisuke;Suzuki, Kenzi
在固定床反应器上，以甲苯为焦油裂解模型化合物，考察了新型镍钙铝催化剂（Ni/Ca 12 Al 14 O33）对生物质焦油水蒸气重整反应的催化性能。制备了Ni/Ca_（12）Al_（14）O_（33）四种催化剂，Ni负载量分别为1、3、5 ~ 7wt%，即使负载量为1%也表现出良好的催化性能。通过BET、X-射线衍射（XRD）和拉曼光谱表征了在不存在（60小时运行）和存在H2S的情况下的催化剂老化实验。结果表明，Ni/Ca_（12）Al_（14）O_（33）催化剂具有良好的抗积炭能力，这是由于催化剂中存在“游离氧”。与工业催化剂Ni/Al 2 O3（5%）和Ni/CaO0.5/MgO0.5相比，该催化剂具有更高的抗H2S中毒性能。拉曼光谱表明，催化剂结构中的“自由氧O-2（-）和O-2（2-）”可被硫取代，从而在一定程度上保护了Ni中毒，但通氧再活化实验表明，硫化物Ni/Ca 12 Al 14 O 33难以完全恢复，O-2只能部分恢复结构中的硫。动力学模型表明，甲苯裂解为一级反应，活化能为82.06 kJ mol（-1），与文献值吻合较好。Ni/Ca_（12）Al_（14）O_（33）催化剂是一种有效的、廉价的催化剂，可降低热煤气净化工艺的成本。(C)2008 Elsevier B. V.保留所有权利。
Newly synthesized nickel calcium aluminum catalysts (Ni/Ca12Al14O33) were tested in a fixed bed reactor for biomass tar steam reforming, toluene as tar destruction model compound. Four catalysts (Ni/Ca12Al14O33) were prepared with Ni loading amount from 1, 3, 5 to 7 wt%, even 1% loading catalyst also showed excellent performance. Catalysts aged experiments in the absence (60 h on stream) and presence of H2S were characterized by BET, X-ray diffraction (XRD), and Raman spectra. It was observed that Ni/Ca12Al14O33 showed excellent sustainability against coke formation due to the "free oxygen" in the catalysts. It also exhibited higher H2S-poisoning resistance property compared to the commercial catalysts Ni/Al2O3 (5%) and Ni/CaO0.5/MgO0.5. Raman spectra revealed that "free oxygen O-2(-) and O-2(2-)" in the structure of the catalysts could be substituted by sulfur then protected Ni poisoning on some degree, but reactivation experiments by 02 flowing showed that the sulfide Ni/Ca12Al14O33 was difficult to completely restore, incorporation of sulfur in the structure only partly regain by O-2. The kinetic model proposes, as generally accepted, a first-order reaction for toluene with activation energy of 82.06 kJ mol(-1) was coincident with the literature data, The Ni/Ca12Al14O33 catalyst was effective and relative cheap, which may be lead to reduction in the cost of hot gas cleaning process. (C) 2008 Elsevier B.V. All rights reserved.