MOF-derived CoFe alloy carbon-supported catalysts with interfacial electron transfer for promoting Fischer−Tropsch synthesis

The direct conversion of carbon monoxide (CO) using green hydrogen is a sustainable approach for producing value-added liquid fuels. This study proposes a novel method to adjust the interface electron structure of Zn₅CoFe₃₅@C catalyst by introducing Fe into MOF-derived carbonized Co carriers, aiming to enhance the production rate of long-chain hydrocarbon products and inhibit CO₂ and methane (CH₄) in Fischer-Tropsch synthesis (FTS). At 350 °C and atmospheric pressure, the optimized Zn₅CoFe₃₅@C catalyst achieves a CO turnover yield (CTY) exceeding 739.29 mmol g_cat⁻¹ h⁻¹, which is 14.03, 2.6 and 1.37 times higher than those of the Co–SiO₂, Co@C and CoFe₃₅@C catalysts, respectively. Interesting, it exhibited a high C₅₊ selectivity of 96.8% and a combined selectivity of less than 5% for unwanted C₁ products. Detailed characterization indicates that the electron transfer between Co and Fe nanometals on the carbon-based support modulates the interface electron structure, facilitating CO adsorption and activation while suppressing CH₄ formation. Furthermore, in the CoFe phase, the electron-rich Co primarily promotes hydrogenation and C–C coupling, while the electron-deficient Fe facilitates intermediate formation through reverse water-gas shift (RWGS), reducing the barriers for C–C coupling. This research enriches the design of highly selective new catalysts for C₁ chemistry and high-value chemicals.