The copper-based catalysts have been generally regarded as high-performance catalysts for CO₂ hydrogenation toward methanol, while the production of ethanol via C-C coupling on the copper-based catalysts is still challenging. Herein, we report a new catalyst where Cu nanoparticles are embedded in the carbon support with abundant defect sites, achieving a high selectivity for ethanol in the CO₂ hydrogenation. The experiments coupled with the theoretical studies show a clear map where carbon defects serve as anchor sites that can stabilize interfacial copper species, and interfacial Cu sites with low coordination numbers can adsorb two C₁ species and later convert them to a C₂ species via a hydrogenation-induced coupling reaction. Further adjacent Cu atoms of interfacial Cu sites can facilitate OH reduction reactions via the Cu-Cu bridge adsorption to assist the formation of ethanol. Especially, those specific active sites easily disappear in the reducing conditions and during the reaction, the major product can transform from ethanol to methanol.

铜基催化剂通常被认为是将CO ₂加氢成甲醇的高性能催化剂，而在铜基催化剂上通过CC偶联生产乙醇仍然具有挑战性。在本文中，我们报道了一种新型催化剂，其中Cu纳米颗粒嵌入具有大量缺陷位点的碳载体中，从而在CO ₂加氢中实现了对乙醇的高选择性。与理论研究相结合的实验显示出一个清晰的图，其中碳缺陷充当了可以稳定界面铜物种的锚定位点，而低配位数的界面Cu位点可以吸收两种C ₁物种，然后将它们转化为C ₂物种通过氢化诱导的偶联反应。界面Cu位点的进一步相邻的Cu原子可通过Cu-Cu桥吸附促进OH还原反应，以帮助乙醇的形成。特别地，那些特定的活性位在还原条件下容易消失，并且在反应过程中，主要产物可以从乙醇转化为甲醇。