4th EucheMs chemistry congress

Poster Session 2
s1207
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - solid state chemistry
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BiMetALLiC niCu nAnoPArtiCLeS Confined in
the MeSoPoreS of SBA-15 AS effeCtive
CAtALyStS in the hydroGenAtion of
CinnAMALdehyde
A. unGureAnu 1 , A. ChirieAC 1 , B. drAGoi 1 ,
S. royer 2 , d. duPrez 2 , e. duMitriu 1
1 “Gheorghe Asachi” Technical University of Iasi, Organic
Biochemical and Food Engineering, Iasi, Romania
2 Université de Poitiers, LACCO UMR 6503 CNRS, Poitiers,
France
Bimetallic nanoparticles (NPs) confined within mesoporous
host structures are emerging as very interesting materials for
catalysis because: (i) as compared with the corresponding
monometallic NPs, they have improved catalytic performances
due to a synergy between the two metals, and (ii) they are highly
sintering-resistant due to the geometric stabilization of NPs inside
the host mesochannels. A novel mild drying impregnation
approach was developed to successfully prepare bimetallic NiCu
rod-like NPs confined within the mesopores of SBA-15 silica (S)
(constant metal loading: 5 wt. %, variable Ni/Cu weight ratios:
4/1, 3/2, 2/3 and 1/4), as shown by low- and high-angle XRD,
nitrogen adsorption/desorption and TEM-EDX. It was observed
that at similar particle size, the composition of bimetallic NPs
determines to a large extent both the reducibility and catalytic
performance in the hydrogenation of cinnamaldehyde (CNA).
Hence, characterization by H -TPR revealed an optimal
2
reducibility at Ni/Cu ratios of 3/2 and 2/3(T ~ 180-240 °C),
red
which is much improved when compared with monometallic Ni/S
and Cu/S reference samples (T ~ 510 and 345 °C, respectively).
red
This is best explained through the existence of strong Ni?Cu
interactions in the bimetallic nanoparticles. The catalytic results
showed an outstanding catalytic activity of the bimetallic
NiCu/S-4/1 catalyst when compared with either Ni/S or Cu/S
-1 -1 (initial reaction rates of 3.212, 1.909 and 0.008 µmol .g .s ,
CNA cat
respectively). As a general trend, the gradual decrease of the
Ni/Cu ratio is followed by a decrease in the catalytic activity of
bimetallic catalysts. Interestingly, the selectivity to cinnamyl
alcohol (measured at X of 20 mol %) continuously increased
CNA
from 1-2 mol % (Ni/S) up to 15-16 mol % (NiCu/S-1/4),
suggesting that the gradual addition of inert Cu to active Ni causes
changes of its geometric and/or electronic properties, which
finally results in enhanced chemoselectivity of NiCu/SBA-15
catalysts.
Acknowledgement: PNII-Idei, 264/2011 financed by
UEFISCDI.
Keywords: Supported catalysts; Nanoparticles; Metals;
Mesoporous materials; Hydrogenation;
4 th EucheMs chemistry congress
P - 0 6 9 0
ChArACterizAtion of CoBALt BASed tPP-BiPy
CoordinAtion PoLyMer
M. K. urtiAGA 1 , A. fidALGo-MAiJuAn 1 ,
G. BArAndiKA 2 , B. BAzán 1 , M. i. ArriortuA 1
1 Universidad del País Vasco (UPV/EHU), Mineralogía y
Petrología, Leioa-Bizkaia, Spain
2 Universidad del País Vasco (UPV/EHU), Química Inorgánica,
Vitoria-Gasteiz, Spain
Metalloporphyrin systems are one of the cornerstones on
which the existence of life is based, as major biochemical,
enzymatic and photochemical functions depend on the special
properties of the tetrapyrrolic macrocycle. [1] The possibility of
introducing porphyrin units into MOFs (metal-organic
frameworks) increases the variety of new materials based on these
macrocycles. During the last years, cobalt porphyrins are
well-known to be prominent catalysts for oxygen reduction
reactions (ORR) [2] and in order to obtain materials which provide
new properties our research group is working with different
combinations of metalloporphyrins and organic ligands . [3]
The work herein presented aims to the characterization of
[CoTPP(bipy)]·[CoTPP] ·TPP (TPP= meso-tetraphenylporphyrin
0.22 0.78
and bipy=4,4'-bipyridine) compound in order to know the thermal,
electronic and catalytic properties of these new porphyrin-based
coordination polymer.
Acknowledgements. This work has been financially supported
by the Ministerio de Ciencia e Innovación (MAT2010-15375)
and the Gobierno Vasco (Basque University System Research
Groups, IT-177-07), which we gratefully acknowledge. SGIker
(UPV/EHU) technical support (MEC, GV/EJ, European Social
Fund) is gratefully acknowledged. A. Fidalgo-Marijuan thanks
the UPV/EHU fellowships.
references:
1. I. Beletskaya, V.S. Tyurin, A.Y. Tsivadze, R. Guilard,
C. Stern, Chem. Rev., 2009, 109, 1659-1713.
2. C. J. Chang, Y. Deng, C. Shi, C.K. Chang, F.C. Anson,
D.G. Nocera, Chem. Commun., 2000, 1355-1356.
3. A. Fidalgo-Marijuan, G. Barandika, B. Bazán,
M. K. Urtiaga, M. I. Arriortua, Polyhedron, 2011, 30,
2711-2716.
Keywords: Porphyrin; Metal-organic frameworks;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc