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 degrees C and atmospheric pressure, the optimized Zn5CoFe35@C catalyst achieves a CO turnover yield (CTY) exceeding 739.29 mmol gcat-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.