Synergy of Oxygen Vacancies and Base Sites for Transfer Hydrogenation of Nitroarenes on Ceria Nanorods

Ziliang Yuan; Liang Huang; Yuanshuai Liu; Yong Sun; Guanghui Wang; Xun Li; Johannes A Lercher; Zehui Zhang

doi:10.1002/anie.202317339

Synergy of Oxygen Vacancies and Base Sites for Transfer Hydrogenation of Nitroarenes on Ceria Nanorods

Angew Chem Int Ed Engl. 2024 Feb 26;63(9):e202317339. doi: 10.1002/anie.202317339. Epub 2024 Jan 17.

Authors

Ziliang Yuan^{1

2}, Liang Huang², Yuanshuai Liu³, Yong Sun⁴, Guanghui Wang², Xun Li¹, Johannes A Lercher^{5

6}, Zehui Zhang¹

Affiliations

¹ Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education &, Hubei Key Laboratory of Catalysis and Materials Science, College of Chemistry and Material Science, South-Central Minzu University, 430081, Wuhan, P. R. China.
² Hubei Key Laboratory of Coal Conversion and New Carbon Material, School of Chemistry and Chemical Engineering &, The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, 430081, Wuhan, P. R. China.
³ Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, (P. R. China).
⁴ Xiamen Key Laboratory of Clean and High-valued Utilization for Biomass, College of Energy, Xiamen University, 361102, Xiamen, P. R. China.
⁵ Department of Chemistry and Catalysis Research Center, Technische Universität München, 85747, Garching, Germany.
⁶ Institute for Integrated Catalysis, Pacific Northwest National Laboratory, 99352, Richland, WA, USA.

PMID: 38085966
DOI: 10.1002/anie.202317339

Abstract

CeO₂ nanorod based catalysts for the base-free synthesis of azoxy-aromatics via transfer hydrogenation of nitroarenes with ethanol as hydrogen donor have been synthesized and investigated. The oxygen vacancies (O_v ) and base sites are critical for their excellent catalytic properties. The O_v , i.e., undercoordinated Ce cations, serve as the sites to activate ethanol and nitroarenes by lowering the energy barrier to transfer hydrogen from α-C_sp3 -H in ethanol to the nitro group coupling it to the redox reactions between Ce³⁺ and Ce⁴⁺ . At the same time, the base sites catalyze the condensation step to selectively produce azoxy-aromatics. The catalytic route opens a much improved way to use non-noble metal oxides without additives for the selective functional group reduction and coupling reactions.

Keywords: Azoxy-Aromatics; Biomass-Derived Ethanol; Ceria Catalysts; Nitroarenes.

Abstract

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