کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
38925 45797 2016 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Low temperature dry reforming of methane on rhodium and cobalt based catalysts: Active phase stabilization by confinement in mesoporous SBA-15
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Low temperature dry reforming of methane on rhodium and cobalt based catalysts: Active phase stabilization by confinement in mesoporous SBA-15
چکیده انگلیسی


• Co nanoparticles are stabilized against sintering in the mesopores of SBA-15 during dry methane reforming.
• The decrease of reduction temperature in presence of Rh leads to more numerous Co species confined in the pores.
• Deactivating carbons are formed in lower amount in presence of both rhodium and cobalt.

Two silica supports either non porous (SiO2) or mesoporous (SBA-15) were impregnated with cobalt (12 wt%) in order to study the confinement effect on catalytic performances in dry reforming of methane. Further increase of activity was obtained by adding small amounts of rhodium (0.2 and 0.5 wt%) to the Co/SBA-15 catalyst. The structural and morphological properties of the calcined samples were characterized by N2 sorption, X-ray diffraction and high-resolution transmission electron microscopy (ultra-thin sections). Their reducibility was studied by temperature-programmed reduction. After in situ reduction of the materials, their catalytic activity was tested in dry reforming of methane up to 800 °C followed by stability testing at 550 °C for 550 min. Cobalt confinement in the mesopores of SBA-15 is shown to be highly beneficial towards not only activity but also stability, the reduced nanoparticles being then more resistant against sintering under stream. Rh plays a role as an additional active phase. It also strongly favors cobalt stabilization in the mesopores by permitting its reduction at a much lower temperature, which allows avoiding metal migration to the surface of the silica grains. The nature of coke is also shown to depend on rhodium addition, with less amount of carbon gamma (graphitic and destructive form) formed on the Rh-containing sample compared to the Rh-free Co/SBA-15 catalyst.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis A: General - Volume 520, 25 June 2016, Pages 114–121
نویسندگان
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