電催化二氧化碳還原反應(CO2 reduction reaction， CO2RR)可在溫和條件下將CO2轉化為高附加價值化學品與燃料，為碳再利用與碳中和能源轉換提供具潛力的途徑。其中，乙醇(C2H5OH)因具有高能量密度、液態儲運便利性及廣泛應用價值，被視為極具吸引力的多碳(C2+)產物。然而，銅(Cu)基觸媒的對CO2反應生成C2H5OH仍受限於*CO中間體供應、*CO吸附強度、C-C耦合效率及含氧C2+中間體穩定性等因素。因此，如何同時調控中間體供應、界面結構穩定性與表面反應環境，是提升將CO2轉換為C2H5OH的關鍵。 本研究提出銀(Ag)與溴化十六烷基三甲銨(Cetyltrimethylammonium bromide， CTAB)雙重修飾策略，合成Ag-Cu2O/Cu@C。此策略透過建立Ag-Cu串聯效應並穩定的銅+1/0價(Cu+/Cu0)界面，提升局部*CO覆蓋度、強化*CO吸附並促進後續C-C耦合。X光電子能譜(X-ray photoelectron spectroscopy， XPS)與X光吸收光譜(X-ray absorption spectroscopy， XAS)結果顯示，雙重修飾可調控Cu表面氧化態、Ag-Cu電子結構與表面氧物種分佈，進而形成有利於C2H5OH生成的表面反應環境。 在-1.0 VRHE下，Ag-Cu2O/Cu@C表現出最佳乙醇選擇性(59.2%)，C2+產物選擇性(72.9%)，顯示其具備優異的C-C耦合能力。此外，Ag-Cu2O/Cu@C在連續電解30小時後仍維持穩定產物選擇性，且反應後未檢測到Cu或Ag溶出，證實雙重修飾策略能有效抑制金屬流失並提升長時間操作穩定性。原位拉曼光譜證實 Ag-Cu2O/Cu@C可同時調控*CO與*OH相關中間體，適中的*COatop與*H吸附有利於C-C耦合。 本研究證明，*CO供應、界面穩定性與表面氧化學環境的協同調控，是提升將CO2轉換為C2H5OH的有效策略。不僅提升了Cu基觸媒的C2H5OH選擇性與操作穩定性，也為未來調控C2+產物分佈及發展高效CO2RR觸媒提供具機制基礎的設計方向。;Electrocatalytic CO2 reduction reaction (CO2RR) can convert CO2 into value-added chemicals and fuels under mild conditions， providing a promising route for carbon reuse and carbon-neutral energy conversion. Among the products， ethanol (C2H5OH) is regarded as an attractive multicarbon (C2+) product because of its high energy density， liquid-state storage and transport advantages， and broad applicability. However， C2H5OH formation on Cu-based catalysts is still limited by the supply of *CO intermediates， *CO adsorption strength， C-C coupling efficiency， and the stability of oxygenated C2+ intermediates. Therefore， simultaneous regulation of intermediate supply， interfacial structural stability， and the surface reaction environment is critical for enhancing CO2-to-C2H5OH conversion. In this study， a dual modification strategy using silver (Ag) and cetyltrimethylammonium bromide (CTAB) was developed to synthesize Ag-Cu2O/Cu@C. This strategy enables the Ag-Cu tandem effect and stabilizes the Cu+/Cu0 interface， enhancing local *CO coverage and *CO adsorption to promote subsequent C-C coupling. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) results show that the dual modification regulates the Cu surface oxidation state， Ag-Cu electronic structure， and surface oxygen species distribution， forming a surface reaction environment favorable for C2H5OH production. At -1.0 VRHE， Ag-Cu2O/Cu@C exhibited the highest C2H5OH selectivity (59.2%)， and C2+ selectivity (72.9%)， demonstrating its excellent C-C coupling capability. In addition， Ag-Cu2O/Cu@C maintained stable product selectivity after 30 h of continuous electrolysis， and no Cu or Ag dissolution was detected after the reaction， confirming that the dual modification strategy effectively suppresses metal leaching and improves long-term operational stability. In-situ Raman spectroscopy further confirmed that Ag-Cu2O/Cu@C can regulate both *CO- and *OH-related intermediates， and that the moderate adsorption between *COatop and *H configuration is favorable for C-C coupling. This study demonstrates that the cooperative regulation of *CO supply， interfacial stability， and surface oxygen chemistry is an effective strategy for enhancing CO2-to-C2H5OH conversion. This strategy not only improves the C2H5OH selectivity and operational stability of Cu-based catalysts but also provides mechanistic guidance for regulating C2+ product distribution and developing efficient CO2RR catalysts.
