A research team headed by Prof. Jie Zeng from University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) created a stable single-site copper coordination polymer that greatly enhanced the efficiency of ethylene production by single-atom catalytic electroreduction of CO2.
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Nature Communications published this research.
Thanks to the high utilization ratio, clear structure, and high selectivity of new single-site catalysts, they have gained great attention. It is usually believed that the reduction of CO2 to polycarbonate products is catalyzed by copper particles, whereas the reduction of CO2 to methane is catalyzed by copper monoatomic catalysts.
It has been found that particular monoatomic catalysts are subjected to agglomeration to develop copper particles in the electrochemical process, which also produce polycarbonate products. But, the way to design stable single-site catalysts for the synthesis of CO2 electro-reduction processes at the same time catalyzing carbon-carbon coupling efficiently is still ambiguous.
In this research, the study group developed a stable single-site copper coordination polymer (Cu(OH)BTA) to understand the successful carbon-carbon coupling process by carbon dioxide electroreduction.
Structural analysis revealed that the coordination polymer exhibited near-neighboring periodic copper sites, and at a suitable copper-copper distance (5.7 Å), carbon-carbon coupling happened without destabilizing the catalyst structure owing to the intermediates’ adsorption, which achieves a successful synthesis of multi-carbon products on a stable single-site catalyst.
The electroreduction of CO2 in the flow cell revealed that the Faradaic efficiency of the multi-carbon product was largely enhanced when compared to the catalyst characteristics of copper metal. The outstanding carbon dioxide electrocatalytic performance of Cu(OH)BTA has been further demonstrated by membrane electrode reaction cell performance evaluation.
A series of features, for example, in situ Raman and in situ X-Ray absorption spectroscopy, confirmed that the mild local environment of this coordination polymer upheld structural stability in the time of electrocatalytic carbon dioxide reduction. The near-neighboring copper sites offered the active center with an appropriate distance for the carbon-carbon coupling process and encouraged the development of the key adsorption intermediate (*OCCHO).
The study offers novel strategies for the development of molecularly stable catalysts for converting and activating carbon dioxide.
Journal Reference:
Liang, Y., et al. (2023). Stabilizing copper sites in coordination polymers toward efficient electrochemical C-C coupling. Nature Communications. doi.org/10.1038/s41467-023-35993-4.
Source: https://en.ustc.edu.cn/