Copper-Iron-Zinc-Cerium oxide compositions as most suitable catalytic materials for the synthesis of green fuels via CO2 hydrogenation

Abstract

Current prospective in the liquid fuels synthesis is prefiguring a greater integration of eco-friendly technologies based on the use of “non-fossil” hydrogen and CO2. Therefore, a series of MOx@CeO2 catalysts (i.e. M = Cu, Fe and Zn), at different MO-to-CeO2 ratio (ca. 0.2–1.5 wt./wt.), were prepared and performed in the in the CO2 hydrogenation reactions at 20 bar and 200–300 °C, (GHSV; 4,400NL∙kg∙cat−1 h−1). Depending on catalyst composition, the CO2 conversion proceeds according to a “volcano shaped” profiles, resulting more effective at an optimal value of interfacial area (i.e. θ = 0.25). This also substantiate that the occurrence of structural-electronic synergistic effects plays a key role in the catalytic properties. The different catalytic pathway of CuZnO@CeO2 and CuFeZnO@CeO2 catalysts prove “dual-sites” and “triple-sites” mechanisms in the CO2 hydrogenation reactions, respectively.