Yue Kaihang, Qin Yanyang, Huang Honghao, Lv Zhuoran, Cai Mingzhi, Su Yaqiong, Huang Fuqiang, Yan Ya
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
Nat Commun. 2024 Sep 7;15(1):7820. doi: 10.1038/s41467-024-52022-0.
Electrochemical reduction of carbon dioxide to produce high-value ethylene is often limited by poor selectivity and yield of multi-carbon products. To address this, we propose a cyanamide-coordinated isolated copper framework with both metallic copper (Cu) and charged copper (Cu) sites as an efficient electrocatalyst for the reduction of carbon dioxide to ethylene. Our operando electrochemical characterizations and theoretical calculations reveal that copper atoms in the CuNCN complex enhance carbon dioxide activation by improving surface carbon monoxide adsorption, while delocalized electrons around copper sites facilitate carbon-carbon coupling by reducing the Gibbs free energy for *CHC formation. This leads to high selectivity for ethylene production. The CuNCN catalyst achieves 77.7% selectivity for carbon dioxide to ethylene conversion at a partial current density of 400 milliamperes per square centimeter and demonstrates long-term stability over 80 hours in membrane electrode assembly-based electrolysers. This study provides a strategic approach for designing catalysts for the electrosynthesis of value-added chemicals from carbon dioxide.
将二氧化碳电化学还原以生产高价值乙烯通常受到多碳产物选择性和产率低的限制。为了解决这个问题，我们提出了一种氰胺配位的孤立铜框架，其具有金属铜（Cu）和带电铜（Cu）位点，作为将二氧化碳还原为乙烯的高效电催化剂。我们的原位电化学表征和理论计算表明，CuNCN络合物中的铜原子通过改善表面一氧化碳吸附来增强二氧化碳活化，而铜位点周围的离域电子通过降低*CHC形成的吉布斯自由能来促进碳-碳偶联。这导致了乙烯生产的高选择性。CuNCN催化剂在每平方厘米400毫安的分电流密度下实现了77.7%的二氧化碳到乙烯转化选择性，并在基于膜电极组件的电解槽中展示了超过80小时的长期稳定性。这项研究为设计用于从二氧化碳电合成增值化学品的催化剂提供了一种策略性方法。
