Synergistic Effects of Cerium and Strontium Promoters on Copper‐Modified Iron‐Based Fischer–Tropsch Synthesis Catalysts

Abstract

As the world shifts towards renewable and sustainable energy sources, converting syngas into hydrocarbons using Fischer–Tropsch synthesis (FTS) catalysts is crucial. In this work, a series of copper‐modified iron‐based catalysts with cerium and strontium promoters supported on γ‐Alumina as follows were prepared using a wet‐impregnation method: FCA (18Fe/4Cu/γ‐Al2O3), FCCA (18Fe/4Cu/2Ce/γ‐Al2O3), FCSA (18Fe/4Cu/2Sr/γ‐Al2O3), and FCCSA (18Fe/4Cu/1Ce/1Sr/γ‐Al2O3). The phase, structure, and morphology of the catalysts were characterized using X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET) specific surface area analysis, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), inductively coupled plasma–atomic emission spectrometry (ICP‐AES), hydrogen temperature‐programmed reduction (H2‐TPR), and hydrogen temperature‐programmed desorption (H2‐TPD). The impacts of Ce and Sr, individually and in combination, on the structure, adsorption, reduction, and catalytic performance of the catalysts were evaluated in a fixed bed reactor at 300°C, 2.0‐MPa pressure, a time of stream of 168 h, and an H2/CO ratio of 1. The CO conversion and product selectivity were calculated using gas chromatography results, highlighting the synergistic effect of Ce and Sr promoters on hydrocarbon product distribution. The doubly promoted FCCSA catalyst exhibited a high CO conversion rate of 77.65%, CO2 selectivity of 43.5%, C2‐C4 selectivity of 55.89%, C5+ selectivity of 85.62.0%, and a yield of 43.19%, surpassing FCA, FCCA, and FCSA catalysts. Similar characteristics, CO conversion, and product selectivity were achieved for FCCSA during long‐term 336‐h FTS runs, indicating stability.