The Malaysian Journal of Analytical Sciences Vol 12
No 1 (2008): 217 – 223
CO2 / H2 METHANATION ON NICKEL OXIDE BASED CATALYST DOPED
WITH VARIOUS ELEMENTS FOR THE PURIFICATION OF NATURAL GAS
Nor Aziah
Buang, Wan Azelee Wan Abu Bakar,
Faridah Mohd Marsin, Mohd
Hasmizam Razali
Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia,
81310, Skudai, Johor.
Abstract
Nickel
possess
characteristics
similar to noble
metals,
apart from
being
easily deactivated
by carbon deposition and poisoning. In this study, the activity of prepared nickel based catalysts doped with selected elements (Mg, Zr, Mo, Mn, Co, Fe, and Cu) that were presumed to help nickel
active sites has been investigated for the CO2
elimination
in the presence of H2 in the hopes for a methanation
reaction. With the addition of lanthanide series as co-dopant
in the catalyst, the synthesized
catalysts were tested for its catalytic activity
and reproducibility by FTIR spectroscopy. It was found
that only several elements can boost CO2 elimination, namely magnesium, cobalt and ferum, with cobalt showing
the highest conversion for
both ratios, Ni/Co/Pr 60:30:10 and 60:10:30.
Furthermore, Ni/Co/Pr with the ratio of 60:30:10 was proven superior
as it yielded highest CH4
in the lowest conversion temperature of approximately 350°C. Further characterization on Ni/Co/Pr
with the ratio of 60:30:10
showed the supremacy towards the conversion
of CO2 to CH4. Single point BET analysis showed that Ni/Co/Pr did not have any changes in the surface area, as it did not adsorb CO2. This statement is in agreement with the XRD and EDX results obtained whereby there are no traces of carbon deposition. From TPD results
showed CO2 desorption peaks
at low and high temperature indicated intermediate bonding
of CO2 on the surface of the catalyst. This shows the
presence of dopant will result in the enhancement
of CO2
elimination to a 100%.
Keywords:
nickel based catalyst, cobalt, CO2
elimination, methanation
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