Controllable C─N Coupling Toward Efficient Urea Electrosynthesis via Spin State Modulation on Fe Catalysts
Abstract
Abstract The co‐electrolysis of CO 2 and nitrate (NO 3 − ) presents a promising and sustainable method for urea synthesis. However, it remains challenging to modulate the intermediates reactivity and C─N coupling at the matchable stages. Here, we propose a strategy to regulate the C─N coupling mode on Fe site via spin state modulation. Both experimental and theoretical calculations revealed that the Cu 2+ ‐doped Fe 3 O 4 promoted C─N coupling at the early stage via the *CO + *NO 2 →*CONO 2 pathway, enhancing the catalytic performance significantly. The catalysts could achieve a urea Faradaic efficiency of 47.3% and a yield rate of 635.9 µg h −1 mg cat. −1 at low overpotential, along with exceptional stability over 30 h, representing one of the highest performances reported to date. Detailed experimental and theoretical analyses demonstrated that Cu doping lowered the e g electron density of Fe and enhanced *NO 2 adsorption. The adsorbed *NO 2 in turn further decreased Fe spin state through π backdonation, which facilitated CO 2 activation and increased *CO coverage. Moreover, optimizing the *NO 2 coverage also reduced the energy barrier for *CO + *NO 2 →*CONO 2 , and inhibited *NO 2 protonation, leading to high selectivity toward urea.
Article Details
Authors (15)
Limin Wu
School of Chemistry and Chemical Engineering
Shunhan Jia
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry
Yongbin Li
College of Life Sciences, Capital Normal University
Chaofeng Zheng
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry
Ruhan Wang
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry
Libing Zhang
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry
Xiangyuan Jin
Beijing National Laboratory for Molecular Sciences Key Laboratory of Colloid and Interface and Thermodynamics Center for Carbon Neutral Chemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China
Rongjuan Feng
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry
Liang Xu
Xinchen Kang
Institute of Chemistry, Chinese Academy of Sciences , , ,
Qinggong Zhu
Institute of Chemistry, Chinese Academy of Sciences , , ,
Qingli Qian
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry
Yi Xu
Xiaofu Sun
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, CAS Research/Education Center for Excellence in Molecular Sciences, Center for Carbon Neutral Chemistry
Buxing Han
Institute of Chemistry, Chinese Academy of Sciences , , ,