کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
56210 47078 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Copper grafted on SBA-15 as efficient catalyst for the selective oxidation of methane by oxygen
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Copper grafted on SBA-15 as efficient catalyst for the selective oxidation of methane by oxygen
چکیده انگلیسی

CuOx/SBA-15 catalysts prepared by a grafting approach (denoted as CuOx/SBA-15-gra) have been characterized and studied for the selective oxidation of methane to formaldehyde by oxygen. Our characterizations using XRD, H2-TPR, UV–vis and ESR suggest that Cu2+ ions are almost isolated on the surface of SBA-15 at a Cu content ≤0.6 wt%. The increase in the Cu content to >0.6 wt% decreased the fraction of isolated Cu2+ ions and increased that of aggregated CuOx clusters. On the other hand, the fraction of isolated Cu2+ ions was much smaller in the CuOx/SBA-15 catalyst prepared by the impregnation method (denoted as CuOx/SBA-15-imp) even with a lower Cu content (0.5 wt%). The CuOx/SBA-15-gra provided significantly higher HCHO selectivity in the selective oxidation of CH4 than the CuOx/SBA-15-imp, and the CuOx/SBA-15-gra catalyst with a Cu content of 0.6 wt% showed the best performance for HCHO formation. In situ FT-IR spectroscopy of adsorbed CO and XPS measurements suggest the generation of Cu+ after the reaction, and the Cu+ site is likely responsible for the activation of oxygen, forming an active oxygen species for the selective oxidation of CH4 to HCHO.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Catalysis Today - Volume 157, Issues 1–4, 17 November 2010, Pages 143–148
نویسندگان
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