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Si J, Zhao G, Sun W, Liu J, Guan C, Yang Y, Shi XR, Lu Y. Oxidative Coupling of Methane: Examining the Inactivity of the MnO x -Na 2 WO 4 /SiO 2 Catalyst at Low Temperature. Angew Chem Int Ed Engl 2022; 61:e202117201. [PMID: 35181983 DOI: 10.1002/anie.202117201] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Indexed: 11/07/2022]
Abstract
Oxidative coupling of methane (OCM) catalyzed by MnOx -Na2 WO4 /SiO2 has great industrial promise to convert methane directly to C2-3 products, but its high light-off temperature is the most challenging obstacle to commercialization and its working mechanism is still a mystery. We report the discovery of a low-temperature active and selective MnOx -Na2 WO4 /SiO2 catalyst enriched with Q2 units in the SiO2 carrier, being capable of converting 23 % CH4 with 72 % C2-3 selectivity at 660 °C. From experiments and theoretical calculations, a large number of Q2 units in the MnOx -Na2 WO4 /SiO2 catalyst is a trigger for markedly lowering the light-off temperature of the Mn3+ ↔Mn2+ redox cycle involved in the OCM reaction because of the easy formation of MnSiO3 . Notably, the MnSiO3 formation proceeds merely through the SiO2 -involved reaction in the presence of Na2 WO4 : Mn7 SiO12 +6 SiO2 ↔7 MnSiO3 +1.5 O2 . The Na2 WO4 not only drives the light-off of this cycle but also gets it working with substantial selectivity toward C2-3 products. Our findings shine a light on the rational design of more advanced MnOx -Na2 WO4 based OCM catalysts through establishing new Mn3+ ↔Mn2+ redox cycles with lowered light-off temperature.
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Affiliation(s)
- Jiaqi Si
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China
| | - Guofeng Zhao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China
| | - Weidong Sun
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China
| | - Jincun Liu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China
| | - Cairu Guan
- School of Physical Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, 201210, China
| | - Yong Yang
- School of Physical Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, 201210, China
| | - Xue-Rong Shi
- Department of Materials Engineering, Shanghai University of Engineering Science, Shanghai, 201620, China
| | - Yong Lu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, East China Normal University, Shanghai, 200062, China.,Institute of Eco-Chongming, Shanghai, 202162, China
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Si J, Zhao G, Sun W, Liu J, Guan C, Yang Y, Shi XR, Lu Y. Oxidative Coupling of Methane: Examining the Inactivity of the MnOx‐Na2WO4/SiO2 Catalyst at Low Temperature. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202117201] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jiaqi Si
- East China Normal University School of chemistry and molecular engineering CHINA
| | - Guofeng Zhao
- East China Normal University School of chemistry and molecular engineering CHINA
| | - Weidong Sun
- East China Normal University School of chemistry and molecular engineering CHINA
| | - Jincun Liu
- East China Normal University Scool of chemistry and molecular engineering CHINA
| | - Cairu Guan
- ShanghaiTech University - Zhangjiang Campus: ShanghaiTech University School of physical Science and Technology CHINA
| | - Yong Yang
- ShanghaiTech University - Zhangjiang Campus: ShanghaiTech University School of physical science and technology CHINA
| | - Xue-Rong Shi
- Shanghai University of Engineering Science - Songjiang Campus: Shanghai University of Engineering Science Department of Materials Engineering CHINA
| | - Yong Lu
- East China Normal University School of Chemistry and Molecular Engineering 3663 North Zhongshan Road 200062 Shanghai CHINA
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