Creating Frustrated Lewis Pairs in Defective Boron Carbon Nitride for Electrocatalytic Nitrogen Reduction to Ammonia

Wenwen Lin; Hao Chen; Gaobo Lin; Siyu Yao; Zihao Zhang; Jizhen Qi; Meizan Jing; Weiyu Song; Jing Li; Xi Liu; Jie Fu; Sheng Dai

doi:10.1002/anie.202207807

Creating Frustrated Lewis Pairs in Defective Boron Carbon Nitride for Electrocatalytic Nitrogen Reduction to Ammonia

Angew Chem Int Ed Engl. 2022 Sep 5;61(36):e202207807. doi: 10.1002/anie.202207807. Epub 2022 Jul 26.

Authors

Wenwen Lin^{1

2}, Hao Chen³, Gaobo Lin^{1

2}, Siyu Yao¹, Zihao Zhang¹, Jizhen Qi⁴, Meizan Jing⁵, Weiyu Song⁵, Jing Li¹, Xi Liu⁶, Jie Fu^{1

2}, Sheng Dai⁷

Affiliations

¹ Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
² Institute of Zhejiang University-Quzhou, 78 Jiuhua Boulevard North, Quzhou, 324000, China.
³ College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, China.
⁴ i-Lab, CAS Center for Excellence in Nanoscience Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences, Suzhou, 215123, China.
⁵ State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum-Beijing, Beijing, 102249, China.
⁶ School of Chemistry and Chemical Engineering, In situ Center for Physical Sciences, Shanghai Jiao Tong University, Shanghai, 200240, China.
⁷ Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.

PMID: 35789179
DOI: 10.1002/anie.202207807

Abstract

The electrocatalytic nitrogen reduction reaction (NRR) on metal-free catalysts is an attractive alternative to the industrial Haber-Bosch process. However, the state-of-the-art metal-free electrocatalysts still suffer from low Faraday efficiencies and low ammonia yields. Herein, we present a molecular design strategy to develop a defective boron carbon nitride (BCN) catalyst with the abundant unsaturated B and N atoms as Lewis acid and base sites, which upgrades the catalyst from a single "Lewis acid catalysis" to "frustrated Lewis pairs (FLPs) catalysis." ¹⁴ N₂ /¹⁵ N₂ exchange experiments and density functional theory (DFT) calculations reveal that FLPs can adsorb an N₂ molecule to form a six-membered ring intermediate, which enables the cleavage of N₂ via a pull-pull effect, thereby significantly reducing the energy barrier to -0.28 eV. Impressively, BCN achieves a high Faraday efficiency of 18.9 %, an ammonia yield of 20.9 μg h^-1 mg^-1 _cat. , and long-term durability.

Keywords: Boron Carbon Nitride; Defects; Electrochemical; Frustrated Lewis Pairs; Nitrogen Fixation.

Abstract

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