Dry reforming of methane over Ni perovskite type oxides
Dry reforming of methane over Ni perovskite type oxides
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DOI：
10.1016/j.cattod.2005.07.010
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发表时间：
2005-10
期刊：
影响因子：
5.3
通讯作者：
Gustavo Valderrama;M. Goldwasser;C. U. Navarro;J. Tatibouët;J. Barrault;C. Batiot-Dupeyrat;F. Martínez-F.-M
中科院分区：
文献类型：
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作者：
Gustavo Valderrama;M. Goldwasser;C. U. Navarro;J. Tatibouët;J. Barrault;C. Batiot-Dupeyrat;F. Martínez-F.-M
采用自燃烧法合成了La 1 − xSrxNiO 3钙钛矿型氧化物，并在700°C和1atm下进行了甲烷与CO2干重整制合成气的催化剂前驱体测试。为了了解催化剂的行为，反应进行了研究，通过脉冲技术使用的CH 4/CO2比接近1。采用X射线衍射（XRD）、BET比表面积、程序升温还原氧化（TPR-TPO）和扫描电子显微镜（SEM）对固体进行了表征。XRD分析表明，钙钛矿的还原是通过形成中间物种进行的，得到Ni 0，La 2 O3和SrO。在所研究的钙钛矿中，LaNiO 3表现出较高的活性，而La 2NiO 4对反应没有活性。结果表明，催化剂的活性随Sr含量的增加而增加，其顺序为：LaNiO 3> La 0.6Sr 0.4NiO 3>Ni（5%）/La 2 O 3> La 0.9Sr 0.1NiO 3。在反应过程中，Ni以Ni 0的形式存在，同时生成SrCO 3和La 2 O2 CO 3相，促进了甲烷重整反应和La 2 O3相的再生。碳形成的缺乏归因于这些相的存在。
La1−xSrxNiO3perovskite type oxides were synthesized by the auto combustion method and tested as catalysts precursors in the dry reforming of methane with CO2to syngas at 700°C and 1atm. In order to understand the catalyst behavior, the reaction was studied by a pulse technique using a CH4/CO2ratio close to one. The solids were characterized by X-ray diffraction (XRD), BET surface area, temperature-programmed reduction and oxidation (TPR-TPO) and scanning electronic microscopy (SEM). XRD analysis showed that reduction of the perovskites proceeds through formation of intermediate species to obtain Ni0, La2O3and SrO. LaNiO3showed the higher activity among the studied perovskites while La2NiO4was not active for the reaction. It was observed that catalytic activity was Sr content dependent, following the order: LaNiO3>La0.6Sr0.4NiO3>Ni (5%)/La2O3>La0.9Sr0.1NiO3. During reaction, nickel remained as Ni0while SrCO3and La2O2CO3phases are formed which improved methane reforming and the regeneration of the La2O3phase. The lack of carbon formation is attributed to the presence of these phases.