energies
Article
Hydrogen Yield from CO
2
Reforming of Methane: Impact of
La
2
O
3
Doping on Supported Ni Catalysts
Ahmed Abasaeed
1
, Samsudeen Kasim
1
, Wasim Khan
1,2,
* , Mahmud Sofiu
1
, Ahmed Ibrahim
1
,
Anis Fakeeha
1,3
and Ahmed Al-Fatesh
1
Citation: Abasaeed, A.; Kasim, S.;
Khan, W.; Sofiu, M.; Ibrahim, A.;
Fakeeha, A.; Al-Fatesh, A. Hydrogen
Yield from CO
2
Reforming of
Methane: Impact of La
2
O
3
Doping on
Supported Ni Catalysts. Energies 2021,
14, 2412. https://doi.org/10.3390/
en14092412
Academic Editors: Vladislav
A. Sadykov and Wasim Khan
Received: 2 March 2021
Accepted: 20 April 2021
Published: 23 April 2021
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1
Chemical Engineering Department, College of Engineering, King Saud University, P.O. Box 800,
Riyadh 11421, Saudi Arabia; abasaeed@ksu.edu.sa (A.A.); sofkolajide2@gmail.com (S.K.);
mahmudsofiu@gmail.com (M.S.); aididwthts2011@gmail.com (A.I.); anishf@ksu.edu.sa (A.F.);
aalfatesh@ksu.edu.sa (A.A.-F.)
2
Department of Chemical and Process Engineering, University of Canterbury, 20 Kirkwood Avenue,
Upper Riccarton, Christchurch 8041, New Zealand
3
King Abdullah City for Atomic & Renewable Energy, Energy Research & Innovation Center (ERIC) in Riyadh,
Riyadh 11451, Saudi Arabia
* Correspondence: wasimkhan49@gmail.com
Abstract: Development of a transition metal based catalyst aiming at concomitant high activity
and stability attributed to distinguished catalytic characteristics is considered as the bottleneck for
dry reforming of methane (DRM). This work highlights the role of modifying zirconia (ZrO
2
) and
alumina (Al
2
O
3
) supported nickel based catalysts using lanthanum oxide (La
2
O
3
) varying from 0 to
20 wt% during dry reforming of methane. The mesoporous catalysts with improved BET surface
areas, improved dispersion, relatively lower reduction temperatures and enhanced surface basicity
are identified after La
2
O
3
doping. These factors have influenced the catalytic activity and higher
hydrogen yields are found for La
2
O
3
modified catalysts as compared to base catalysts (5 wt% Ni-ZrO
2
and 5 wt% Ni-Al
2
O
3
). Post-reaction characterizations such as TGA have showed less coke formation
over La
2
O
3
modified samples. Raman spectra indicates decreased graphitization for La
2
O
3
catalysts.
The 5Ni-10La
2
O
3
-ZrO
2
catalyst produced 80% hydrogen yields, 25% more than that of 5Ni-ZrO
2
.
5Ni-15La
2
O
3
-Al
2
O
3
gave 84% hydrogen yields, 8% higher than that of 5Ni-Al
2
O
3
. Higher CO
2
activity improved the surface carbon oxidation rate. From the study, the extent of La
2
O
3
loading is
dependent on the type of oxide support.
Keywords: Al
2
O
3
; CO
2
reforming; La
2
O
3
; CH
4
; ZrO
2
1. Introduction
The decrease of fossil fuel energy and the dilemma of environmental pollution urged
a large number of researchers to maximize the conversions of methane and carbon dioxide
into useful products such as hydrogen. Hydrogen is a benign source of energy. It is mainly
obtained from biomass pyrolysis and thermal reforming. Methane, the main component
of natural gas, can be obtained from various resources like shale gas and the fracking
process, which has increased the availability of natural gas from infrequent deposits [1,2].
Moreover, the utilization of biogas is gaining momentum in recent years [3,4]. In the field
of heterogeneous catalysis, particularly, in the latest decades, dry reforming of methane
is regarded as one of the best prospective ways of conversion [5–7]. However, the dry
reforming reaction as shown in Equation (1) is highly endothermic and thus requires high
reaction temperatures. The process produces synthesis gas that has an appropriate ratio of
H
2
to CO suitable for Fischer–Tropsch synthesis [8]. Steam reforming of methane remains
the best available industrial process for generating synthesis gas [9,10]. The requirement
and the utilization of synthesis gas production are continuously increasing [11]. During
methane dry reforming (DRM), CO
2
is employed as an oxidant, which draws the interest
Energies 2021, 14, 2412. https://doi.org/10.3390/en14092412 https://www.mdpi.com/journal/energies