Lithium carbonate-promoted mixed rare earth oxides as a generalized strategy for oxidative coupling of methane with exceptional yields

Kun Zhao; Yunfei Gao; Xijun Wang; Bar Mosevitzky Lis; Junchen Liu; Baitang Jin; Jacob Smith; Chuande Huang; Wenpei Gao; Xiaodong Wang; Xin Wang; Anqing Zheng; Zhen Huang; Jianli Hu; Reinhard Schömacker; Israel E Wachs; Fanxing Li

doi:10.1038/s41467-023-43682-5

Lithium carbonate-promoted mixed rare earth oxides as a generalized strategy for oxidative coupling of methane with exceptional yields

Nat Commun. 2023 Nov 27;14(1):7749. doi: 10.1038/s41467-023-43682-5.

Authors

Kun Zhao^{1

2}, Yunfei Gao³, Xijun Wang⁴, Bar Mosevitzky Lis⁵, Junchen Liu¹, Baitang Jin¹, Jacob Smith¹, Chuande Huang⁶, Wenpei Gao¹, Xiaodong Wang⁶, Xin Wang⁷, Anqing Zheng², Zhen Huang², Jianli Hu⁸, Reinhard Schömacker⁹, Israel E Wachs¹⁰, Fanxing Li¹¹

Affiliations

¹ North Carolina State University, Campus Box 7905, Raleigh, NC, USA.
² CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, China.
³ Institute of Clean Coal Technology, East China University of Science and Technology, Shanghai, China. yunfeigao@ecust.edu.cn.
⁴ Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA.
⁵ Operando Molecular Spectroscopy & Catalysis Laboratory, Department of Chemical & Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA.
⁶ Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
⁷ Institute of Clean Coal Technology, East China University of Science and Technology, Shanghai, China.
⁸ Department of Chemical & Biomedical Engineering, West Virginia University, Morgantown, WV, USA.
⁹ Department of Chemistry, Technische Universität Berlin, Straße des 17. Juni 124, Berlin, Germany.
¹⁰ Operando Molecular Spectroscopy & Catalysis Laboratory, Department of Chemical & Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA. iew0@lehigh.edu.
¹¹ North Carolina State University, Campus Box 7905, Raleigh, NC, USA. fli5@ncsu.edu.

Abstract

The oxidative coupling of methane to higher hydrocarbons offers a promising autothermal approach for direct methane conversion, but its progress has been hindered by yield limitations, high temperature requirements, and performance penalties at practical methane partial pressures (~1 atm). In this study, we report a class of Li₂CO₃-coated mixed rare earth oxides as highly effective redox catalysts for oxidative coupling of methane under a chemical looping scheme. This catalyst achieves a single-pass C₂₊ yield up to 30.6%, demonstrating stable performance at 700 °C and methane partial pressures up to 1.4 atm. In-situ characterizations and quantum chemistry calculations provide insights into the distinct roles of the mixed oxide core and Li₂CO₃ shell, as well as the interplay between the Pr oxidation state and active peroxide formation upon Li₂CO₃ coating. Furthermore, we establish a generalized correlation between Pr⁴⁺ content in the mixed lanthanide oxide and hydrocarbons yield, offering a valuable optimization strategy for this class of oxidative coupling of methane redox catalysts.

Abstract

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