کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1526748 | 1511849 | 2008 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Effect of Ni-modified α-Al2O3 prepared by sol–gel and solvothermal methods on the characteristics and catalytic properties of Pd/α-Al2O3 catalysts Effect of Ni-modified α-Al2O3 prepared by sol–gel and solvothermal methods on the characteristics and catalytic properties of Pd/α-Al2O3 catalysts](/preview/png/1526748.png)
In the present study, Ni-modified α-Al2O3 with Ni/Al ratios of 0.3 and 0.5 were prepared by sol–gel and solvothermal method and then were impregnated with 0.3 wt.% Pd. Due to different crystallization mechanism of the two preparation methods used, addition of nickel during preparation of α-Al2O3 resulted in various species such as NiAl2O4, mixed phases between NiAl2O4 and α-Al2O3, and mixed phases between NiAl2O4 and NiO. As revealed by NH3-temperature programmed desorption, formation of NiAl2O4 drastically reduced acidity of alumina, hence lower amounts of coke deposited during acetylene hydrogenation was found for the Ni-modified α-Al2O3 supported catalysts. For any given method, ethylene selectivity was improved in the order of Pd/Ni–Al2O3-0.5 > Pd/Ni–Al2O3-0.3 > Pd/Ni–Al2O3-0 ≫ Pd/α–Al2O3-commercial. When comparing the samples prepared by different techniques, the sol–gel-made samples showed better performances than the solvothermal-derived ones.
Journal: Materials Chemistry and Physics - Volume 111, Issues 2–3, 15 October 2008, Pages 431–437