MnTiO 3 -driven low-temperature oxidative coupling of methane over TiO 2 -doped Mn 2 O 3 -Na 2 WO 4 /SiO 2 catalyst
In: Science Advances, Jg. 3 (2017-06-02)
Online
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Zugriff:
Oxidative coupling of methane (OCM) is a promising method for the direct conversion of methane to ethene and ethane (C2 products). Among the catalysts reported previously, Mn2O3-Na2WO4/SiO2 showed the highest conversion and selectivity, but only at 800° to 900°C, which represents a substantial challenge for commercialization. We report a TiO2-doped Mn2O3-Na2WO4/SiO2 catalyst by using Ti-MWW zeolite as TiO2 dopant as well as SiO2 support, enabling OCM with 26% conversion and 76% C2-C3 selectivity at 720°C because of MnTiO3 formation. MnTiO3 triggers the low-temperature Mn2+↔Mn3+ cycle for O2 activation while working synergistically with Na2WO4 to selectively convert methane to C2-C3. We also prepared a practical Mn2O3-TiO2-Na2WO4/SiO2 catalyst in a ball mill. This catalyst can be transformed in situ into MnTiO3-Na2WO4/SiO2, yielding 22% conversion and 62% selectivity at 650°C. Our results will stimulate attempts to understand more fully the chemistry of MnTiO3-governed low-temperature activity, which might lead to commercial exploitation of a low-temperature OCM process.
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MnTiO 3 -driven low-temperature oxidative coupling of methane over TiO 2 -doped Mn 2 O 3 -Na 2 WO 4 /SiO 2 catalyst
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Autor/in / Beteiligte Person: | Pengwei, Wang ; Yong, Lu ; Yu, Wang ; Guofeng, Zhao |
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Zeitschrift: | Science Advances, Jg. 3 (2017-06-02) |
Veröffentlichung: | American Association for the Advancement of Science (AAAS), 2017 |
Medientyp: | unknown |
ISSN: | 2375-2548 (print) |
DOI: | 10.1126/sciadv.1603180 |
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