Product Yields Dependency on the Carbide Phase Presence in Cobalt and Iron SBA-15 Catalysts Structure in the Fischer–Tropsch Synthesis

Abstract

The use of carbide catalysts in Fischer–Tropsch synthesis (FTS) is an active area of research, as carbide phases have been shown to improve the stability and performance of catalysts in this reaction. This study compared the catalytic activity and product selectivity of cobalt and iron catalysts supported on SBA-15, with and without a carbide phase and reduction treatment before the reaction. Results showed that the presence of the carbide phase had a noticeable influence on the catalytic behavior of the catalysts, and the reduction of the catalyst with hydrogen also affected the product selectivity. The presence of the carbide phase in non-reduced cobalt catalysts resulted in increased selectivity to liquid phase products, as evidenced by a CO conversion of 37% with 68% selectivity to the products in the liquid phase. The catalytic activity of the iron carbide catalyst for CO dissociation was found to be 38% after reducing the catalyst with hydrogen, leading to the formation of more active sites. The presence of metal carbides and formation of metallic cobalt and iron during the FT reaction and reduction step was found to have a significant effect on the catalytic performance and product selectivity. The findings of this research provide new insights into the role of carbide in the performance of cobalt and iron catalysts in Fischer–Tropsch synthesis.

Fischer–Tropsch synthesis over the Co–Ni/Al2O3 nanocatalyst: influence of process variables, modeling and optimization using response surface methodology

“…After catalyst activation and CO hydrogenation reaction in the spent sample CoO (cubic), Ni (rhombohedral), Co 3 C (orthorhombic), NiC (cubic) and Co (cubic) phases were found. Assessment of XRD results showed that oxidic phases of fresh catalyst along with activation and FTS processes changed into carbide and metallic phases; it has been reported that these phases are active for FTS 35,36 …”

“…Assessment of XRD results showed that oxidic phases of fresh catalyst along with activation and FTS processes changed into carbide and metallic phases; it has been reported that these phases are active for FTS. 35,36 Scanning electron microscopy The SEM technique was employed for investigating the morphological characteristics and particle aggregation of samples.…”