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High Efficiency Electrochemical Nitrogen Fixation Achieved with a Lower Pressure Reaction System by Changing the Chemical Equilibrium
Author(s) -
Cheng Hui,
Cui Peixin,
Wang Fangrui,
Ding LiangXin,
Wang Haihui
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201910658
Subject(s) - ammonia production , electrochemistry , faraday efficiency , ammonia , chemistry , nitrogen , catalysis , chemical engineering , ambient pressure , dissolution , reversible reaction , inorganic chemistry , thermodynamics , electrode , organic chemistry , physics , engineering
Abstract We demonstrate a simple and effective chemical equilibrium regulation strategy to improve the efficiency of electrochemical ammonia synthesis by constructing electrochemical reaction system that works at significantly lower pressure than the Haber–Bosch process. Transferring the nitrogen reduction reaction from ambient conditions to a lightly pressurized environment not only accelerates the activation of the N≡N triple bond but also inhibits the competing reaction of hydrogen evolution while promoting the dissolution and diffusion of nitrogen. The verification experiment of using well‐designed Fe 3 Mo 3 C/C composite nanosheets as the nitrogen reduction catalyst shows that the lower pressure reaction system can improve the Faradaic current efficiency by one order of magnitude. Moreover, the comparatively low‐pressure reaction system can greatly reduce the cell voltage of the ammonia synthesis reaction (up to 33 %) even at the relatively low pressure of 0.7 MPa, which is of significance for decreasing the energy consumption of electrochemical ammonia synthesis under mild conditions.