Unveiling Electrochemical Urea Synthesis by Co-Activation of CO2 and N2 with Mott-Schottky Heterostructure Catalysts

Menglei Yuan; Junwu Chen; Yiling Bai; Zhanjun Liu; Jingxian Zhang; Tongkun Zhao; Qin Wang; Shuwei Li; Hongyan He; Guangjin Zhang

doi:10.1002/anie.202101275

Unveiling Electrochemical Urea Synthesis by Co-Activation of CO₂ and N₂ with Mott-Schottky Heterostructure Catalysts

Angew Chem Int Ed Engl. 2021 May 3;60(19):10910-10918. doi: 10.1002/anie.202101275. Epub 2021 Apr 8.

Authors

Menglei Yuan^{1

2}, Junwu Chen^{1

2}, Yiling Bai^{3

4}, Zhanjun Liu^{2

3}, Jingxian Zhang^{1

2}, Tongkun Zhao^{1

2}, Qin Wang⁵, Shuwei Li^{1

2}, Hongyan He^{1

2}, Guangjin Zhang^{1

2

6}

Affiliations

¹ CAS Key Laboratory of Green Process Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
² Center of Materials Science and Optoeletronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
³ CAS Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, P. R. China.
⁴ SynCat@Beijing, Synfuels China Technology Co. Ltd, Beijing, 101407, P. R. China.
⁵ Engineering Design Department, Hebei Enco Petrochemical Engineering Co. Ltd., Henan Branch, Henan, 450000, P. R. China.
⁶ Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515031, P. R. China.

PMID: 33634560
DOI: 10.1002/anie.202101275

Abstract

Electrocatalytic C-N bond coupling to convert CO₂ and N₂ molecules into urea under ambient conditions is a promising alternative to harsh industrial processes. However, the adsorption and activation of inert gas molecules and then the driving of the C-N coupling reaction is energetically challenging. Herein, novel Mott-Schottky Bi-BiVO₄ heterostructures are described that realize a remarkable urea yield rate of 5.91 mmol h^-1 g^-1 and a Faradaic efficiency of 12.55 % at -0.4 V vs. RHE. Comprehensive analysis confirms the emerging space-charge region in the heterostructure interface not only facilitates the targeted adsorption and activation of CO₂ and N₂ molecules on the generated local nucleophilic and electrophilic regions, but also effectively suppresses CO poisoning and the formation of endothermic *NNH intermediates. This guarantees the desired exothermic coupling of *N=N* intermediates and generated CO to form the urea precursor, *NCON*.

Keywords: C-N coupling; Mott-Schottky heterostructures; electrocatalysis; urea.

Abstract

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