Activity of Fe supported by Ce
1x
Sm
x
O
2d
derived from metal complex
decomposition toward the steam reforming of toluene as biomass tar
model compound
Apirat Laobuthee
a, *
, Chatchai Veranitisagul
b
, Worawat Wattanathana
c
,
Nattamon Koonsaeng
c
, Navadol Laosiripojana
d, e, **
a
Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand
b
Department of Materials and Metallurgical Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi,
Pathumthani 12110, Thailand
c
Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
d
The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
e
PTT Group Frontier Research Center, PTT Public Company Limited, 555 Vibhavadi Rangsit Road, Chatuchak, Bangkok 10900, Thailand
article info
Article history:
Received 5 April 2014
Accepted 1 August 2014
Available online
Keywords:
Samaria doped ceria
Biomass tar
Reforming
Hydrogen
abstract
Ceria (CeO
2
) and samaria doped ceria (Ce
1x
Sm
x
O
2d
) powders with various Ce/Sm ratios have been
successfully prepared via metal complex decomposition. The catalytic activities of these synthesized
materials toward the steam reforming of toluene as model compound of biomass tar were studied with
an aim to determine the suitable catalyst for biomass tar decomposition in biomass gasification system.
From the study, H
2
, CO, CO
2
, CH
4
,C
2
H
4
and C
2
H
6
were the main products from the reaction with low
carbon deposition observed on the catalyst surface after 18 h operation. Among all catalysts, relatively
higher toluene conversion and H
2
yield (32.8%) with greater resistance toward carbon deposition was
achieved from Ce
0.85
Sm
0.15
O
2d
. To enhance better toluene conversion and H
2
yield, Ce
0.85
Sm
0.15
O
2d
was
further applied as the catalyst support by impregnating low-cost Fe on its surface; and its reforming
activity was compared to Ni and Fe supported over conventional g-Al
2
O
3
. It was found that, Fe/
Ce
0.85
Sm
0.15
O
2d
offered significantly higher toluene conversion and H
2
yield than Fe/Al
2
O
3
(55.2% H
2
yield compared to 16.5%). Its reforming activity was also comparable to Ni/Al
2
O
3
with better H
2
yield
stability after 72 h operation (16% deactivation for Fe/Ce
0.85
Sm
0.15
O
2d
compared to 35% deactivation for
Ni/Al
2
O
3
). Therefore, Fe/Ce
0.85
Sm
0.15
O
2d
has good potential to replace Ni-based catalyst in biomass
gasification system.
© 2014 Elsevier Ltd. All rights reserved.
1. Introduction
Ceria (CeO
2
) is a mixed ionic electronic conductive material
which can be reduced the electronic conductivity by doping triva-
lent cations, such as La
2
O
3
, Gd
2
O
3
, and Sm
2
O
3
[1e3]. The doped
ceria exhibiting superior ionic conductivity has been, therefore,
considered as an electrolyte in the solid oxide fuel cell (SOFC).
Owing to a high mobility of oxygen vacancies created in the lattice
acting as sources for oxygen associated in reactions on the ceria
surface, ceria has been also applied as catalysts in the oxidation,
partial oxidation including methane reforming. [1e5].
Recently, our group found that Ce
x
Gd
y
Sm
z
O
2
synthesized by
metal organic complex method showed the catalytic activity for
methane steam reforming under moderate temperatures [6]. This
preparation method also provides the materials with fluorite
structure and ultrafine particles after calcined at 900
C. Moreover,
as comparing with doping contents of samaria and gadolinia in
CeO
2
, it was also found that samaria exhibited the high and
reversible oxygen storage capacity (OSC) leading to the good
methane steam reforming performance rather than gadolinia [6]. In
this present work, ceria (CeO
2
) and the samaria doped ceria
(Ce
1x
Sm
x
O
2d
) powders were prepared from the metal complex
decomposition which exhibits many benefits in terms of a simple
and effective method, low processing temperatures, and the
* Corresponding author. Tel.: þ66 2 797 0999 ext 2132; fax: þ66 2 955 1811.
** Corresponding author. Tel.: þ66 2 470 8309 ext 4146; fax: þ66 2 872 6736.
E-mail addresses: fengapl@ku.ac.th (A. Laobuthee), navadol_l@jgsee.kmutt.ac.th
(N. Laosiripojana).
Contents lists available at ScienceDirect
Renewable Energy
journal homepage: www.elsevier.com/locate/renene
http://dx.doi.org/10.1016/j.renene.2014.08.001
0960-1481/© 2014 Elsevier Ltd. All rights reserved.
Renewable Energy 74 (2015) 133e138