Magnetic resonance imaging studies on catalyst impregnation processes: discriminating metal ion complexes within millimeter-sized gamma-Al2O3 catalyst bodies

Magnetic resonance imaging (MRI) was used to study the impregnation step during the preparation of Ni/gamma-Al(2)O(3) hydrogenation catalysts with Ni(2+) metal ion present in different coordinations. The precursor complexes were [Ni(H(2)O)(6)](2+) and [Ni(edtaH(x))]((2-x)-) (where x = 0, 1, 2 and ed...

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Vydáno v:	Journal of the American Chemical Society Ročník 131; číslo 18; s. 6525
Hlavní autoři:	Espinosa-Alonso, Leticia, Lysova, Anna A, de Peinder, Peter, de Jong, Krijn P, Koptyug, Igor V, Weckhuysen, Bert M
Médium:	Journal Article
Jazyk:	angličtina
Vydáno:	United States 13.05.2009
ISSN:	1520-5126, 1520-5126
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Popis
Shrnutí:	Magnetic resonance imaging (MRI) was used to study the impregnation step during the preparation of Ni/gamma-Al(2)O(3) hydrogenation catalysts with Ni(2+) metal ion present in different coordinations. The precursor complexes were [Ni(H(2)O)(6)](2+) and [Ni(edtaH(x))]((2-x)-) (where x = 0, 1, 2 and edta = ethylenediaminetetraacetic acid), representing a nonshielded and a shielded paramagnetic complex, respectively. Due to this shielding effect of the ligands, the dynamics of [Ni(H(2)O)(6)](2+) or [Ni(edtaH(x))]((2-x)-) were visualized applying T(2) or T(1) image contrast, respectively. MRI was applied in a quantitative manner to calculate the [Ni(H(2)O)(6)](2+) concentration distribution after impregnation when it was present alone in the impregnation solution, or together with the [Ni(edtaH(x))]((2-x)-) species. Moreover, the combination of MRI with UV-vis microspectroscopy allowed the visualization of both species with complementary information on the dynamics and adsorption/desorption phenomena within gamma-Al(2)O(3) catalyst bodies. These phenomena yielded nonuniform Ni distributions after impregnation, which are interesting for certain industrial applications.
Bibliografie:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	1520-5126 1520-5126
DOI:	10.1021/ja900346k