10
th
International Symposium “Scientific Bases for the Preparation of Heterogeneous Catalysts”
E.M. Gaigneaux, M. Devillers, S. Hermans, P. Jacobs, J. Martens and P. Ruiz (Editors)
© 2010 Elsevier B.V. All rights reserved.
Design of nano-sized FeOx and Au/FeOx catalysts
for total oxidation of VOC and preferential
oxidation of CO
S. Albonetti
a
, R. Bonelli
a
, R. Delaigle
c
, E.M. Gaigneaux
c
, C. Femoni
b
,
P.M. Riccobene
d
, S. Scirè
d
, C. Tiozzo
b
, S. Zacchini
b,
F. Trifirò
a
.
a
Dip. Chimica industriale e dei Materiali, Viale Risorgimento 4, 40136 Bologna, Italy -
INSTM, Research Unit of Bologna, Italy
b
Dip. Chimica Fisica ed Inorganica, Viale Risorgimento 4, 40136 Bologna, Italy.
c
Unité de Catalyse et Chimie des Matériaux Divisés, Université catholique de Louvain
(UCL), Croix du Sud 2/17, 1348 Louvain-la-Neuve (Belgium).
d
Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria 6, 95125
Catania, Italy.
Abstract
A novel preparation method was developed for the preparation of iron and gold/iron
supported catalysts using metallic carbonyl clusters as precursors of highly dispersed
nanoparticles over TiO
2
and CeO
2
. A series of catalysts with different metal loadings
were prepared and tested in the complete oxidation of methanol and the preferential
oxidation of CO in the presence of H
2
(PROX) as model reactions. The characterization
by BET, XRD, TEM, H
2
-TPR, ICP-AES and XPS spotlights the interaction between Au
and Fe and their influence on the catalytic activity.
1. Introduction
It has been recently reported that gold/iron catalysts exhibit high performances in the
total oxidation of different molecules. Moreover, it was proven that the addition of iron
to supported gold catalysts leads to improved activity and stability during CO oxidation
[1,2]. Since it is well known that the catalytic behavior of multi-component supported
catalysts is strongly influenced by the size of the metal particles and by their reciprocal
interaction, we tried to develop a methodology for the preparation of iron stabilized gold
nanoparticles with controlled size and an intimate contact between the active phases
starting from bimetallic carbonyl clusters. In this paper we report the study on the pre-
paration of FeOx and Au/FeOx catalysts supported on TiO
2
and CeO
2
utilizing homo-
and bimetallic carbonyl cluster salts, i.e. [NEt
4
][HFe
3
(CO)
11
] and [NEt
4
][AuFe
4
(CO)
16
],
and their activity in the total oxidation of methanol and PROX reaction.
2. Experimental
2.1. Catalysts preparation
Au/FeOx catalysts have been prepared by impregnation of the bimetallic carbonyl
cluster salt [NEt
4
][AuFe
4
(CO)
16
] on the support, TiO
2
(DT51 Millennium powder) or
CeO
2
(VP AdNano Ceria 90 Evonik). The required amount of the carbonyl cluster was
dissolved in degassed acetone (20-40 mL) under nitrogen and added dropwise over a
period of 1 hour to an acetone suspension of the support (10-15 g), previously degassed
and stored under nitrogen. The resulting suspension was allowed to stir overnight then
the solvent was removed in vacuum at room temperature. Following a similar procedure,