کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
62761 47654 2008 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structural and reactive relevance of V+NbV+Nb coverage on alumina of VNbO/Al2O3 catalytic systems
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Structural and reactive relevance of V+NbV+Nb coverage on alumina of VNbO/Al2O3 catalytic systems
چکیده انگلیسی

Vanadium and niobium species (together and separately) were loaded on gamma alumina, and the resulting catalysts were run in the methanol conversion. This reaction was studied by both GC analysis and FTIR study in the flow system. The catalytic properties are discussed based on the combined FTIR and 27Al, 51V and 1H MAS NMR studies. The NMR studies revealed a different mechanism of interaction between Nb and Al2O3 than that between V and Al2O3. This predetermines the structure of vanadium sites in bimetallic VNb/Al samples. The effect of coverage was considered for various metal loadings ranging from below to above monolayer. One of our most interesting findings is that the surface Nb oxide species exhibited a redox character below monolayer but were acidic above monolayer. 27Al MAS NMR revealed a strong alumina–Nb interaction that may account for its redox performance. Moreover, the role of sulfate from vanadium precursor is evidenced.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Catalysis - Volume 255, Issue 1, 1 April 2008, Pages 94–103
نویسندگان
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