Stolyarchuk I. Catalytic properties of nanoscale ferrites МIIFeIII2O4 in the ethanol steam reforming process

The thesis is devoted to the establishment of the relationship between the chemical composition of nanosized ferrites with spinel structure MIIFeIII2O4 (M = Mg, Mn, Fe, Co, Ni, Cu, Zn) and their catalytic properties in the process of ethanol steam reforming for hydrogen production using water-alcohol mixtures, which simulates bioethanol. It was found that Mn-, Mg- and Fe-containing catalysts are characterized by the highest activity and hydrogen selectivity. It was established that the active phase of these catalysts is oxide phase because the catalysts remained in the unreduced state in the steam reforming conditions. It was shown that the formation of the target products of steam reforming (H2 and CO2) is determined by the rate of oxidation-reduction transformations in pairs of Fe3+ (or M3+) ↔ Fe2+ (or M2+), which, in turn, depends on the chemical composition and structure of the ferrospinel. A new effective catalyst for the steam reforming of bioethanol based on nanosized manganese ferrite has been developed. The target process over MnFe2O4 is characterized by a close to stoichiometry hydrogen yield of 94.6% (5.68 mole H2 per one mole of inlet ethanol) at 650 °C; no CO was detected in the reaction products, that is important for the use of hydrogen in low-temperature fuel cells.