Efficient C-N coupling for urea electrosynthesis on defective Co3O4 with dual-functional sites
Pengsong Li1,2, Qinggong Zhu1,2, Jiyuan Liu1,2
1Beijing 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, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China qgzhu@iccas.ac.cn hanbx@iccas.ac.cn.
Chemical Science
|March 1, 2024
Summary
Defective cobalt oxide (Co3O4) catalysts efficiently produce urea from CO2 and nitrite via electrocatalysis. Oxygen vacancies optimize reactant binding, enhancing urea yield and selectivity for fine chemical synthesis.
Area of Science:
- Electrocatalysis
- Materials Science
- Green Chemistry
Background:
- Urea electrosynthesis offers an alternative to traditional methods but suffers from low efficiency due to competing reaction pathways caused by weak reactant binding.
- Developing catalysts with optimized adsorption properties is crucial for efficient urea production.
Purpose of the Study:
- To synthesize defective Co3O4 catalysts with dual-functional sites for efficient urea electrosynthesis from CO2 and nitrite.
- To investigate how regulating reactant adsorption on defective Co3O4 catalysts influences competing reaction pathways.
Main Methods:
- Synthesis of defective Co3O4 catalysts.
- Electrochemical measurements to assess urea production rate, faradaic efficiency, and carbon selectivity.
- Experimental and theoretical investigations (e.g., DFT) to understand reaction mechanisms and active sites.
Main Results:
- Achieved a high urea yield rate of 3361 mg h-1 gcat-1 with 26.3% faradaic efficiency and 100% carbon selectivity at -0.7 V vs. RHE.
- Demonstrated that oxygen vacancies in Co3O4 create well-matched adsorption sites, optimizing intermediate binding and reducing C-N coupling energy.
- Showcased effective control over competing reaction pathways by tuning reactant adsorption capacity.
Conclusions:
- Defective Co3O4 catalysts with integrated dual-functional sites enable efficient urea electrosynthesis.
- Oxygen vacancies are key to optimizing catalyst performance by improving reactant adsorption and facilitating C-N coupling.
- This research provides insights for designing non-noble transition metal oxide catalysts for synthesizing C-N fine chemicals.
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