Conversion from CO₂ to the more desirable and valuable C₂₊ products under neutral conditions is important for the development of energy and the environment, but it is a challenging work. In this work, we demonstrate that the bi-copper sites on the crystal surface of a metal–organic framework Cu-HITP (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) are very suitable for catalyzing the low-energy pathway of *CO coupling with *COH to form *OCCOH. The in situ infrared spectroscopy, theoretic calculations, and controlled experiments show that polydopamine coating of Cu-HITP could provide a carbon dioxide reduction reaction-favored local environment with proton sources and hydrogen-bond donors around the bi-copper active sites to promote *CO hydrogenation and stabilize the key intermediates (*COH and *OCCOH), resulting in a high selectivity of the C₂₊ reduced products [Faradaic efficiency (C₂₊) of 75(3)%, Faradaic efficiency (C₂H₄) of 51(1)%] in the KHCO₃ electrolyte. This work provides an insight into the catalytic activity on the surface of metal–organic frameworks and the local environment for electroreduction of CO₂ to C₂₊ products.

中文翻译：

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具有双铜位点的金属有机框架的聚多巴胺涂层，用于将 CO2 高选择性电还原为 C2+ 产物

在中性条件下将CO ₂转化为更理想和更有价值的C ₂₊产品对于能源和环境的发展很重要，但这是一项具有挑战性的工作。在这项工作中，我们证明了金属有机骨架Cu-HITP（HITP = 2,3,6,7,10,11-六亚氨基苯并苯）晶体表面上的双铜位点非常适合催化低- *CO 与 *COH 耦合形成 *OCCOH 的能量通路。原位红外光谱、理论计算和对照实验表明，Cu-HITP的聚多巴胺涂层可以提供一个有利于二氧化碳还原反应的局部环境，在双铜活性位点周围具有质子源和氢键供体，以促进*CO氢化并稳定关键中间体（*COH和*OCCOH），从而产生高选择性KHCO ₃电解液中的C ₂₊还原产物[法拉第效率(C ₂₊ ) 为75(3)%，法拉第效率(C ₂ H ₄ ) 为51(1)%] 。这项工作提供了对金属-有机框架表面的催化活性和将 CO ₂电还原为 C ₂₊产物的局部环境的深入了解。