کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
60502 | 47535 | 2016 | 6 صفحه PDF | دانلود رایگان |
• High intrinsic hydrogenation activity of Ni promoted WS2 catalyst.
• Efficient preparation method using molecular precursors of tungsten and nickel.
• Quasi hexagonal morphology of NiWS crystallites highlighted by HAADF-STEM.
• Quantification of Ni distribution by a multi-technique approach.
• Distribution of Ni promoter atoms at the edge tuned by the preparation method.
An efficient preparation method – based on the grafting and deposition of Ni and W molecular precursors onto partially dehydroxylated amorphous silica–alumina followed by a thermal treatment under H2S/H2 – generates supported NiWS catalysts exhibiting enhanced activities in toluene hydrogenation, by comparison with conventional samples, prepared from metallic salts. A careful analysis of these materials by IR, XPS, TEM, HAADF-STEM, together with DFT calculations, reveals that the improved activity probably originates from the lower sulfidation temperature of W that improves distribution of Ni–W mixed sites at the edges of NiWS crystallites. This provides an optimal compromise between intrinsic activity and surface concentration of active sites.
Figure optionsDownload high-quality image (163 K)Download as PowerPoint slide
Journal: Journal of Catalysis - Volume 340, August 2016, Pages 60–65