Influence of sugars in preparing improved FeAl catalyst for carbon dioxide hydrogenation

Abstract The influences of sugars (sucrose, fructose and glucose) on the performance of FeAl catalysts were investigated for CO 2 hydrogenation. FeAl catalysts were prepared with two steps. At first, the catalyst precursors were obtained by co-precipitation. During this step, three methods were used to add sucrose into the precursors. Then, promoter K and Cu were impregnated into the precursors. The improved CO 2 conversion and C 5+ hydrocarbon selectivity by sucrose addition were attributed to the formation of γ-Fe 2 O 3 phase in the catalyst precursor, which was different from the popular opinion that sucrose acted as a chelating agent. With the inspiration from sucrose hydrolysis effect, FeAl oxide, mainly in γ-Fe 2 O 3 phase was prepared by adding fructose and glucose (the products of sucrose hydrolysis) into the newly centrifuged precipitate. The formation of γ-Fe 2 O 3 phase was explained based on the results of XRD and XPS. The best catalyst possessed CO 2 conversion of 30.3% and C 5  + selectivity of 52.2% under the reaction conditions of H 2 :CO 2  = 3:1, 6.0 L/(h·g-cat), 1.6 MPa and 235 °C. Graphic abstract Effects of fructose and glucose on FeAl catalyst