Manganese oxide forms prepared by different methods differ by their compositions, phase ratios in polyphase samples, and crystallite sizes (XRD and TEM characterization). Among the phases, tunnel-structured β-MnO2 (pyrolusite), α-MnO2 (cryptomelane), ε-MnO2 (akhtenskite), and β-Mn2O3 (bixbyite) have been identified. Water vapor sorption isotherms showed substantial differences in the affinities of water molecules to oxide surfaces of the manganese oxide forms under study. The parameters of the BET equation and pore size distribution curves have been calculated. The manganese oxide forms have mesoporous structures characterized by uniform and non-uniform pore sizes as well as by moderate hydrophilic behavior.

Pillared clays (PILCs) are little-studied as supports in compositions of anchored metal complex catalysts. In the work, pillared clay, Al-PILC, was prepared by using Ukrainian natural bentonite, N-Bent, and the aluminum polycation, [Al 13 O 4 (OH) 24 (H 2 O) 12 ] 7+ (Al 13), as an intercalating agent. The final product was used for preparing К 2 PdCl 4-Cu(NO 3) 2-KBr/ Al-PILC nanocatalysts by an impregnation method. Initial N-Bent and Al-PILC as well as the nanocompositions based on them were characterized by XRD, FT-IR spectroscopy, DTG-DTA, water vapor adsorption, and pH metry. К 2 PdCl 4-Cu(NO 3) 2-KBr/S compositions (S were N-Bent or Al-PILC) were tested in the reaction of CO oxidation with air oxygen at temperature of 20 °C and a relative humidity of 67%. It has been found that the preliminary modification of natural bentonite by Al 13 intercalation results in formation of the nanostructured catalyst with a crystallite size of 19 nm showing the maximum activity in the reaction under study at C Pd(II) = 2.72 × 10 −5 mol/g and copper(II) concentrations of 2.9 × 10 −5 and 5.9 × 10 −5 mol/g.

No abstract

Copper(II) and palladium(II) adsorption from single-component, Cu(NO 3) 2 or K 2 PdCl 4 , and twocomponent Cu(NO 3) 2-K 2 PdCl 4 aqueous solutions by bentonites provided by two different Ukrainian deposits was investigated in this study. As was found, types of the obtained adsorption isotherms depended on the bentonite origin, the nature of the adsorbed metal ion and the component quantity in the aqueous solutions under study. The most complicated adsorption isotherms were obtained for Pd(II) adsorption from the single-component Pd(II) and two-component Pd(II)-Cu(II) solutions. The adsorption of each metal ion decreased in the presence of the second one being evidence of competitive adsorption and confirming the nonhomogenity of adsorption sites.

The effect of halide ions (X= Cl−, Br−, I−) on the kinetics of ozone decomposition by compositions supported on the natural bentonite of the Dashukovske deposit in Ukraine (N-Bent(D)) has been studied. The obtained results have shown that the activity of the KX/N-Bent(D) composition in the ozone decomposition reaction increases in the row KCl << KBr < KI, which correlates with an increase in their reducing properties (the redox potential of the Х2/2Х− pair decreases). Such catalyst compositions can be recommended for applying in personal protective equipment for the respiratory system.