کد مقاله کد نشریه سال انتشار مقاله انگلیسی ترجمه فارسی نسخه تمام متن
38688 45787 2016 10 صفحه PDF ندارد دانلود رایگان
عنوان انگلیسی مقاله
On the detectability limits of nickel species on NiO/γ-Al2O3 catalytic materials
ترجمه فارسی عنوان
درباره حدود قابلیت آشکارسازی گونه های نیکل بر روی مواد کاتالیزوری NiO/γ-Al2O3
کلمات کلیدی
کاتالیزورهای نیکل آلومینا؛ کاتالیزورهای بودن؛ سمیت کاتالیزورهای صرف؛ پراکندگی نیکل؛ آلومینا؛ اسپینل سطح
Nickel-alumina catalysts; Spent catalysts; Toxicity of spent catalysts; Dispersion of nickel; Alumina; Surface spinel
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
چکیده انگلیسی


• NiO/Al2O3 mechanical mixtures and impregnated samples were prepared and analysed.
• By increasing Ni loading: dispersed Ni2+, surface spinel, 2 types of NiO were noticeable.
• Carcinogenic and easily reducible NiO is detected with a sensitivity limit <1000 ppm.
• Also the surface spinel NixAl2O3+x (x ≤ 0.25) is detected with sensitivity <1000 ppm.
• Carcinogenic NiAl2O4 does not form at temperatures up to 1073 K.

NiO/Al2O3 mechanical mixtures and impregnated catalytic materials have been prepared and analysed by XRD, DR-UV–vis-NIR, skeletal FT-IR, XPS, FE-SEM techniques. The presence of the carcinogenic and easily reducible NiO phase (bunsenite) is detected by XRD, DR-vis and DR-NIR with a sensitivity limit well lower than 1000 ppm, which is the lower limit by law to classify a NiO-containing waste, such as spent catalysts, as dangerous. This species is also observed by XPS and FE-SEM with a similar sensitivity limit. Hardly reducible surface dispersed Ni2+ species are also observed by DR-vis with a sensitivity limit lower than 1000 ppm. A surface spinel-like phase, with a composition NixAl2O3+x, with x ≤ 0.25 is formed at higher loadings, and is distinguished from the highly dispersed Ni2+ species using IR and XRD. This defective surface spinel like species can be distinguished from stoichiometric bulk NiAl2O4 by applying DR-NIR spectroscopy. The stoichiometric bulk nickel aluminate phase NiAl2O4 (which is also classified as carcinogenic) does not form from γ-Al2O3 or δ-Al2O3 and nickel species at temperatures up to 1073 K.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis A: General - Volume 525, 5 September 2016, Pages 180–189
نویسندگان
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