Affiliation:
1. State Key Lab of Fine Chemicals School of Chemical Engineering Dalian University of Technology Dalian 116024 China
2. School of Chemistry and Chemical Engineering Anhui Key Laboratory of Coal Clean Conversion and High Valued Utilization Anhui University of Technology Maanshan 243002 China
Abstract
AbstractCo electroreduction of carbon dioxide and nitrate to synthesize urea provides an alternative strategy to high energy‐consumption traditional methods. However, the complexity of the reaction mechanism and the high energy barrier of nitrate reduction result in a diminished production of urea. Herein, a convenient electrodeposition technique to prepare the FeOOH with low spin state iron that increases the yield rate of urea efficiently is employed. According to soft X‐ray Absorption Spectroscopy and theoretical calculations, the unique configuration of low spin state iron as electron acceptors can effectively induce electron pair transfer from the occupied σ orbitals of intermediate *NO to empty d orbitals of iron. This σ→d donation mechanism leads to a reduction in the energy barrier associated with the rate‐determining step (*NOOH→*NO + *OH), hence augmenting the urea generation. The low spin state iron presents a high urea yield rate of 512 µg h−1 cm−2, representing approximately two times compared to the medium spin state iron. The key intermediates (*NH2 and *CO) in the formation of C─N bond are detected with in situ Fourier transform infrared spectroscopy. The coupling of *NH2 and *CO contributes to the formation of *CONH2, which subsequently endures multi‐step proton‐coupled electron transfer to generate urea.
Funder
National Natural Science Foundation of China
Fundamental Research Funds for the Central Universities
Natural Science Foundation of Shandong Province
Dalian High-Level Talent Innovation Program
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry