Efficient Ammonia Electrosynthesis from Pure Nitrate Reduction via Tuning Bimetallic Sites in Redox‐Active Covalent Organic Frameworks
Abstract
Abstract Electrocatalytic nitrate reduction reaction (NITRR) represents a promising approach for ammonia synthesis, but existing application has been constrained by the complex proton‐coupled electron transfer and the sluggish kinetics induced by various intermediates. Herein, we synthesized a series of metalized covalent organic frameworks: NiTP‐MTAPP MCOFs (M = 2H, Co, Cu, and Fe), based on dual redox‐active centers: thiophene‐substituted Ni‐bis(dithiolene) ligand‐Ni[C 2 S 2 (C 4 H 2 SCHO) 2 ] 2 and metallic porphyrin. Through regulating the adsorption and desorption of species at the catalytic sites, we have identified the optimal NITRR electrocatalyst: NiTP‐CoTAPP MCOF, which achieved the highest faradaic efficiency (FE) of approximately 85.6% at −0.8 V (vs. RHE) in pure nitrate solution, with an impressive yield rate of 160.2 mmol h −1 g −1 cat. The generation of active hydrogen at [NiS 4 ] sites achieved dynamic equilibrium with the timely hydrogenation reaction at CoN 4 sites, effectively suppressing the hydrogen evolution reaction. Moreover, the incorporation of thiophene (TP) groups and metal ions facilitates charge transfer. Density functional theory (DFT) calculations demonstrated the reduction in energy barriers at different catalytic sites. The CoN 4 −NiS 4 system exhibited the optimal adsorption‐to‐desorption capability and the lowest energy barrier (0.58 eV) for the rate‐determining step (*NO → *HNO), which is supported by the moderate d‐band center and Bader charge value.
Article Details
Authors (13)
Zedong Zhang
School of Materials Science and Engineering
Miao Wang
Hao‐Ran Xing
State Key Laboratory of Coordination Chemistry MOE Key Laboratory of Mesoscopic Chemistry MOE Key Laboratory of High Performance Polymer Materials and Technology Jiangsu Key Laboratory of Advanced Organic Materials Institute of Theoretical and Computational Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing Jiangsu 210023 P.R. China
Xiaocheng Zhou
State Key Laboratory of Coordination Chemistry, Key Laboratory of Mesoscopic Chemistry of MOE, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering
Lei Gao
Shizheng Chen
State Key Laboratory of Coordination Chemistry MOE Key Laboratory of Mesoscopic Chemistry MOE Key Laboratory of High Performance Polymer Materials and Technology Jiangsu Key Laboratory of Advanced Organic Materials Institute of Theoretical and Computational Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing Jiangsu 210023 P.R. China
Yinjuan Chen
Hui Xu
Wei Li
Shuai Yuan
State Key Laboratory of Coordination Chemistry, Key Laboratory of Mesoscopic Chemistry of MOE, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering
Cheng‐Hui Li
State Key Laboratory of Coordination Chemistry MOE Key Laboratory of Mesoscopic Chemistry MOE Key Laboratory of High Performance Polymer Materials and Technology Jiangsu Key Laboratory of Advanced Organic Materials Suzhou Key Laboratory of Green Intelligent Manufacturing of New Energy Materials and Devices Tianchang New Materials and Energy Technology Research Center Institute of Green Chemistry and Engineering School of Chemistry and Chemical Engineering Nanjing University Nanjing Jiangsu 210023...
Zhong Jin
State Key Laboratory of Coordination Chemistry, MOE Key Laboratory of Mesoscopic Chemistry, MOE Key Laboratory of High Performance Polymer Materials and Technology, Jiangsu Key Laboratory of Green Energy Catalysis and Intelligent Chemical Engineering, Suzhou Key Laboratory of Green Intelligent Manufacturing of New Energy Materials and Devices, Tianchang New Materials and Energy Technologies Research Center, Institute of Green Chemistry and Engineering, School of Chemistry and Chemical Engineering
Jing‐Lin Zuo
State Key Laboratory of Coordination Chemistry MOE Key Laboratory of Mesoscopic Chemistry MOE Key Laboratory of High Performance Polymer Materials and Technology Jiangsu Key Laboratory of Advanced Organic Materials Institute of Theoretical and Computational Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing Jiangsu 210023 P.R. China