A palladium species bound to an exopolysaccharide (Pd-EPS) was obtained from alive bacterial cells of Klebsiella oxytoca BAS-10 grown in static mode in the presence of Pd(NO3)2. Pd-EPS, after isolation and purification, was used as catalyst in the aqueous biphasic hydrogenation either of unfunctionalyzed olefins, as styrene, 1-octene and 1,3-diisopropenylbenzene, or of some -unsaturated aldehydes. The catalytic system was very active under mild reaction conditions and its activity was maintained in some recycle experiments. Even more efficient was the “activated Pd-EPS”, obtained by a pre-treatment of Pd-EPS with 1 MPa of H2 at 30°C for 21h; while Pd-EPS originally contains only Pd(II), as demonstrated by XPS measurements, the activated catalyst shows the presence of both Pd(II) and Pd(0) in the ratio 1.9/1. The two catalytic systems show different structures at TEM observations evidencing the transformation of electron ultradense nanoaggregates (Pd-EPS) into jagged microaggregates (“activated Pd-EPS”).
|Data di pubblicazione:||2013|
|Titolo:||Aqueous biphasic hydrogenations catalyzed by new biogenerated Pd-polysaccharide species|
|Rivista:||APPLIED CATALYSIS A: GENERAL|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.apcata.2012.10.040|
|Appare nelle tipologie:||2.1 Articolo su rivista |
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|Reprint idrogenazioni Pd-EPS.pdf||Documento in Post-print||Licenza non definita||Riservato|