• • Co1Fe1Na1 catalyst achieved 45% total alcohol selectivity and 94.1% C2+ alcohol fraction at 260 °C and 2.0 MPa, demonstrating a viable route for higher alcohol synthesis from syngas.
• • Na promoter induced Co-Fe alloy formation during reaction, while Fe enhanced Co reducibility and oxygen vacancy concentration, as confirmed by XPS and TPR, enabling dual-site synergy.
• • In situ spectroscopy and post-reaction analysis confirmed coexistence of Co-Fe alloy and carbide phases (Co2C, FeCx), which balanced CO dissociation and insertion, suppressing over-hydrogenation and chain overgrowth.
• • The catalyst design achieves high C2+ alcohol selectivity (94.1%) at moderate conditions (260 °C, 2 MPa), offering a promising alternative to noble-metal-based systems for industrial application.