Farbun I. Citric acid aided synthesis and physico-chemical properties of dispersed oxides of 3d-metals (Zn, Cu, Ni, Mn) and cerium

The thesis deals with in-depth studies of the citric acid aided synthesis of dispersed materials based on oxides of 3d-metals and cerium and with analyses of their structural and catalytic properties. Proposed initial concentrations of reactants (0,5 М solutions of the nitrates of 3d-metals and cerium and 1,0 М solution of citric acid) and parameters of the synthesis (рН of initial mixture 2,8-3,2, metal ion to citric acid ratio of 1:2, the thermal treatment temperature of 673 К) allow for obtaining mesoporous materials of maximal specific surface area (up to 113 m2/g) and a great micropore fraction (16-20 %), small particle size (<100 nm) and small aggregation. It has been shown for the first time that for mixed oxides of CuO-CeO2 and MnOx- CeO2 compositions at great contents of the second component, just the citric acid aided route leads to the formation of substitution solid solutions. Differences in the morphology of the samples obtained serve as screening criteria for the selection of the most efficient oxidation catalysts. Catalytic tests reveal that the mixed oxides under study may be used as catalysts for purifying hydrogen in fuel cells from CO admixtures and for oxidation of volatile organic compounds (ethyl acetate, ethanol, benzene, toluene, n-buthane) containing in pipe gases.