Journal Article

PUBDB-2015-04252

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png XAS analysis of iron and palladium bonded to a polysaccharide produced anaerobically by a strain of Klebsiella oxytoca

Arcon, I. (Corresponding author)>Extern* ; Paganelli, S. ; Piccolo, O. ; Gallo, M. ; Vogel-Mikuš, K.>Extern* ; Baldi, F.

2015
IUCr Chester

This record in other databases:        

Please use a persistent id in citations: doi:10.1107/S1600577515010371

Abstract: Klebsiella oxytoca BAS-10 ferments citrate to acetic acid and CO2, and secretesa specific exopolysaccharide (EPS), which is able to bind different metallicspecies. These biomaterials may be used for different biotechnological purposes,including applications as innovative green biogenerated catalysts. In productionof biogenerated Pd species, the Fe(III) as ferric citrate is added to anaerobicculture of K. oxytoca BAS-10, in the presence of palladium species, to increasethe EPS secretion and improve Pd-EPS yield. In this process, bi-metallic (FePd-EPS) biomaterials were produced for the first time. The morphology of bimetallicEPS, and the chemical state of the two metals in the FePd-EPS, areinvestigated by transmission electron microscopy, Fourier transform infra-redspectroscopy, micro-X-ray fluorescence, and X-ray absorption spectroscopymethods (XANES and EXAFS), and compared with mono-metallic Pd-EPS andFe-EPS complexes. Iron in FePd-EPS is in the mineralized form of iron oxides/hydroxides, predominantly in the form of Fe3+, with a small amount of Fe2+ inthe structure, most probably a mixture of different nano-crystalline iron oxidesand hydroxides, as in mono-metallic Fe-EPS. Palladium is found as Pd(0) in theform of metallic nanoparticles with face-centred cubic structure in both bimetallic(FePd-EPS) and mono-metallic (Pd-EPS) species. In bi-metallic species,Pd and Fe nanoparticles agglomerate in larger clusters, but they remain spatiallyseparated. The catalytic ability of bi-metallic species (FePd-EPS) in a hydrodechlorinationreaction is improved in comparison with mono-metallic Pd-EPS.

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Contributing Institute(s):

1. DOOR-User (DOOR)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)
2. FS-Proposal: I-20110511 EC (I-20110511-EC) (I-20110511-EC)
3. CALIPSO - Coordinated Access to Lightsources to Promote Standards and Optimization (312284) (312284)

Experiment(s):

1. DORIS Beamline C (DORIS III)

Appears in the scientific report 2015

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Database coverage:
; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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