Highly productive and robust core@shell HeatPath SiC-Al2O3 @Co/Re/Al2O3 catalyst for Fischer–Tropsch synthesis

Abstract

Co-based catalysts are highly active for synthesizing long-chain paraffins through Fischer–Tropsch synthesis. However, their exothermic reactions can cause overheating and catalyst deactivation. To address this, thermally conductive SiC-Al2O3 pellets (HeatPath™) were coated with a Co/Re/Al2O3 shell, significantly boosting the CO conversion rate and the yield of C2–4 and C5+ hydrocarbons over a wide range of temperatures by dissipating the reaction heat. The core@shell HeatPath@Co/Re/Al2O3 catalyst demonstrated high productivity (up to 19.7 gCOgcat−1 h−1), exceptional long-term stability over 660 h time-on-stream, with high-temperature operation up to 260 °C, a low CH4 selectivity (7.1 %) and a chain growth probability (α) > 0.8. In contrast, the irreversible deactivation of a powder Co/Re/Al2O3 catalyst started at 195 °C, resulting in >60 % CH4 selectivity and ∼100 % CO conversion due to excessive local heat. The CO conversion rate on the core@shell catalyst could be further improved by increasing the H2/CO ratio and temperature, with commercially viable CH4 selectivity.