Tailoring the yttrium content in Ni-Ce-Y/SBA-15 mesoporous silicas for CO2 methanation
A series of nickel-cerium-promoted mesoporous silica (SBA-15) catalysts modified with different loadings of yttrium were synthesized by cetyltrimethylammonium bromide (CTAB)-assisted impregnation. The catalysts were tested in CO2 methanation reaction and characterized by N2 sorption, X-ray fluoresce...
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Published in: | Catalysis today 2021-12, Vol.382, p.104-119 |
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Main Authors: | , , , , , , , |
Format: | Article |
Language: | eng |
Subjects: | |
Online Access: | Get full text |
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Summary: | A series of nickel-cerium-promoted mesoporous silica (SBA-15) catalysts modified with different loadings of yttrium were synthesized by cetyltrimethylammonium bromide (CTAB)-assisted impregnation. The catalysts were tested in CO2 methanation reaction and characterized by N2 sorption, X-ray fluorescence (XRF), small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (XRD), H2 chemisorption, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR), CO2 temperature-programmed desorption (CO2-TPD), and thermogravimetric analysis coupled with mass spectrometry (TGA-MS). The best catalytic performance in CO2 methanation was found for Y-modified NiCe/SBA-15 catalysts compared to the unpromoted sample. The modification with 10 wt% of yttrium gave the highest CO2 conversion of 61% ± 2% at 350 °C. We attribute this increase to an improved dispersion of Ni, increased reducibility of Ni species, higher ratio of Ce3+/(Ce3+ + Ce4+), and increased moderate basicity found for 15Ni10Ce10Y/SBA-15. This paper shows that 10 wt% of Y loading not only improves the catalytic activity in CO2 methanation, but also gives stable performance. The tested 15Ni10Ce10Y/SBA-15 catalyst did not exhibit activity loss during 26 h of time-on-stream (TOS) experiment at 350 °C. Moreover, carbon deposits and sintered nickel particles could hardly be found in 15Ni10Ce10Y/SBA-15 catalyst used for 7 h.
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•Y promotion of Ni-Ce/SBA-15 catalyst significantly improved the catalytic activity in CO2 methanation.•10 wt% loading of Y showed the highest CO2 conversion at 350 °C.•Y promotion led to higher reducibility of nickel species.•Higher ratio of Ce3+/(Ce3+ + Ce4+) was found for 10 wt% Y modified Ni-Ce/SBA-15 catalyst.•10 wt% Y modified Ni-Ce/SBA-15 catalyst showed high stability in CO2 methanation. |
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ISSN: | 0920-5861 1873-4308 |