The support effect on the performance of a MOF-derived Co-based nano-catalyst in Fischer Tropsch synthesis

Abstract

The catalyst plays a central role in the Fischer–Tropsch synthesis (FTS) process, and the choice of catalyst support significantly impacts FTS catalyst performance by enhancing its attributes. In this study, the effects of utilizing various metal oxides-CeO₂, ZrO₂, and TiO₂-on a cobalt-based FTS nanocatalyst are investigated by evaluating the catalyst's reducibility, stability, syngas chemisorption, intermediate species spillover, charge transfer, and metal–support interaction (MSI). This evaluation is conducted both theoretically and experimentally through diverse characterization tests and molecular dynamics (MD) simulations. Characterization tests reveal that the ceria-supported catalyst (Ceria Nano Catalyst, CNC) demonstrates the highest reducibility, stability, CO chemisorption, and spillover, while the zirconia-supported catalyst (Zirconia Nano Catalyst, ZNC) exhibits the highest hydrogen chemisorption and spillover. The MD simulation results align well with these findings; for instance, ZNC has the lowest hydrogen adsorption enthalpy (ΔH_Ads.), whereas CNC has the lowest ΔH_Ads. for CO. Additionally, MD simulations indicate that the titania-supported catalyst (Titania Nano Catalyst, TNC) possesses the highest MSI value, closely resembling that of ZNC, albeit with a minor difference. The TNC catalyst's performance in other tests is also similar to that of ZNC. Finally, FTS performance tests illustrate that the ZNC catalyst achieves the highest CO conversion at 88.1%, while the CNC catalyst presents the lowest CO conversion at 82.2%. Notably, the CNC catalyst showcases the highest durability, with only a 4.4% loss in CO conversion and an 8.55% loss in C₅₊ yield after 192 h of operation.