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RESEARCH ARTICLE
Advanced Science Letters
Vol. 23, 5977–5979, 2017
Packed and Monolithic Reactors for the Dry
Reforming of Methane: Ni Supported on
-Al
2
O
3
Promoted by Ru
I. Luisetto
1 *
, C. Sarno
2
, D. De Felicis
3
, F. Basoli
4
, C. Battocchio
1
, S. Tuti
1
, E. Bemporad
3
,
S. Licoccia
2
, and E. Di Bartolomeo
2
1
Department of Sciences, “Roma Tre” University, Via della Vasca Navale 79, 00146 Rome, Italy
2
Department of Chem. Sci. and Technologies, “Tor Vergata” University, Via della Ricerca Scientifica, 00133 Rome, Italy
3
Department of Engineering, “Roma Tre” University, Via della Vasca Navale 79, 00146 Rome, Italy
4
Department of Engineering, “Campus Bio-Medico di Roma” University, Via Álvaro del Portillo 21, 00128 Rome, Italy
The Dry reforming of methane (DRM) is as an efficient way for CH
4
and CO
2
valorisation because the produced
syn-gas has an H
2
/CO ratio equal to that suitable for the synthesis of oxygenated hydrocarbons and synthetic
fuels. The development of Ni (10 wt%) based structured and unstructured catalysts promoted by a small amount
of Ru (0.5 wt%) has been investigated. Unstructured catalysts were prepared by wet impregnation method
and a combination of wash coating-wet impregnation methods was used for cordierite monoliths. Ru promoted
catalyst (Ni–Ru) was remarkable active showing higher reactant conversions and H
2
/CO ratio compared with
Ni catalyst. Ni–Ru monolith was initially much more active than monometallic Ni stating the positive effect of
Ru on maintaining Ni reduced. Reaching steady state condition, Ni rapidly deactivated due to carbon formation,
whereas Ni–Ru monolith remained stable confirming that Ru behaves as an efficient and cheap promoter of Ni
for DRM.
Keywords: Ni/Al
2
O
3
, NiRu/Al
2
O
3
, Structured Catalyst, Dry Reforming of Methane, Carbon Deposition.
1. INTRODUCTION
The CO
2
reforming of CH
4
(Eq. (1)) or dry reforming (DRM) is
as an efficient way of recycling two greenhouse gases to syn-gas.
1
CH
4
+ CO
2
→ 2H
2
+ 2CO H
0
298 K
= 247 kJmol
-1
(1)
To date, the DRM industrial implementation is mainly impeded
by catalyst deactivation and/or reactor plugging due to the
methane cracking (Eq. (2)).
CH
4
→ C + 2H
2
H
0
298 K
= 75 kJmol
-1
(2)
Therefore, there is a pressing need to increase the catalysts
resistance toward carbon deposition, one mean being the use
of noble metal, such as Pt, Ru and Rh, supported on various
oxides.
2
Among bimetallic systems, best performances are shown
by those containing a small amount (<1 wt%) of precious metals
keeping the catalyst cost sufficiently low for industrial imple-
mentation. Ruthenium is the cheapest precious metal and for this
*
Author to whom correspondence should be addressed.
reason can be the ideal choice as a promoter. Ni–Ru catalysts
have been studied for the DRM reaction
3
showing very good cat-
alytic activity and stability due to an increased Ni dispersion. As
yet, it has not been completely clarified if the effect of Ru is to
promote the formation of Ni–Ru alloys or to favour Ni disper-
sion. Moreover, being the solubility between Ni and Ru metals
quite limited, some authors claim a very low Ni sintering resis-
tance by Ru addition.
4
Beside the definition of the catalyst proper
characteristics, it is also important to fulfil the demands arising
from industrial production and process intensification. For this
purpose, the use of micro-structured catalysts can offer several
advantages over conventional packed bed reactors: increase of
mass and heat transfer, lower pressure drop, larger surface-to-
volume ratio and compact reactor design.
5
In the present work
we investigated the effect of a small amount of Ru (0.5 wt%)
on the catalytic activity and stability toward carbon deposition
and Ni oxidation of Ni/ -Al
2
O
3
catalysts for the DRM reac-
tion. Ni and Ni–Ru based catalysts were studied in both powder
and structured forms. Cordierite monolith was selected because
of its chemical stability and thermal compatibility with alumina
catalyst.
Adv. Sci. Lett. Vol. 23, No. 6, 2017 1936-6612/2017/23/5977/003 doi:10.1166/asl.2017.9085 5977