Enhanced Fischer-Tropsch synthesis via hierarchical MOF-derived FeCo nanocatalysts: A MOF-on-MOF strategy

چکیده مقاله

We report a novel approach to Fischer-Tropsch synthesis (FTS) catalyst design through the strategic integration of mesoporous PCN-600(Fe) and microporous ZIF-67(Co) metal-organic frameworks (MOFs). The synthesis involves controlled pyrolysis of PCN-600(Fe), ZIF-67(Co), and their hybrid ZIF-67(Co)@PCN-600(Fe) precursors under inert conditions to generate Fe@CN, Co@CN, and bimetallic FeCo@CN catalysts, respectively. Under optimized high-temperature FT conditions at 320 °C and 6 atm, the FeCo@CN catalyst demonstrated exceptional performance with 76.5 % CO conversion and balanced selectivity toward C₂C₄ (43.6 %) and C₅⁺ (35.4 %) hydrocarbons, outperforming the monometallic Fe@CN (71.4 % conversion) and Co@CN (46.6 % conversion) catalysts. This improved performance arises from the cooperative features of the bimetallic system, including hierarchical porosity inherited from PCN-600(Fe), well-dispersed Fe and Co sites, and strong metal-nitrogen coordination. Comprehensive characterization using FT-IR, XRD, FESEM, EDX mapping, ICP, TGA, BET, XPS and TEM confirmed the structural properties and composition of the materials. This work demonstrates that MOF-on-MOF growth is an effective strategy for designing heterogeneous catalysts with hierarchical porosity and spatially organized active sites. The porous, stable bimetallic MOF framework mitigates metal particle aggregation and sintering, while enabling a nuanced distribution of metal–nitrogen–like coordination environments that underpin to catalytic performance. Copyright © 2025. Published by Elsevier B.V.