Mg−Zn and Mn−Zn Ferrites Derived from Coil Core Materials as New Precursors for Catalysts of Primary Alcohols Transformations

Abstract

Two new precursor materials, (Mg 0.63 Zn 0.37 )(Mn 0.1 Fe 1.8 )O 3.85 (hereafter Mg-Zn) and (Mn 0.55 Zn 0.35 Fe 0.1 )Fe 2 O 4 (hereafter Mn-Zn), derived from the microelectronic ferrite materials studied earlier by us, were found to be catalytically active in primary alcohols transformation. Both Mg-Zn and Mn-Zn ferrites reveal dehydrogenating features, transforming a primary alcohol into an aldehyde, but they differ with respect to subsequent bimolecular condensation to symmetric ketone. The difference in selectivity can be tentatively explained by the different dispersion of surface both Lewis acidic centers and reducing centers as well as the presence of a strong synergic effect between these centers. The materials were tested by XRD, TPR, IR, and BET methods.

Synthesis and characterization of manganese–zinc ferrite obtained by thermal decomposition from organic precursors

“…Owing to their developed specific surface and high surface energy they can be used as catalysts [1][2][3] or gas sensors [4]. Nanoferrites with belowcritical grain size at room temperature are characterized by superparamagnetism, low Curie temperature, and high magnetic flux density.…”

Mg–Zn and Mn–Zn Ferrites Derived from Coil Core Materials as New Phenol Methylation Catalysts

“…11 Consequently, Mg−Zn and Mn−Zn, i.e., (Mg 0.63 Zn 0.37 )(Mn 0.1 Fe 1.8 )O 3.85 and (Mn 0.55 Zn 0.35 Fe 0.1 )Fe 2 O 4 ferrites, 12 were used as catalysts for transformations of the primary alcohol. 13 The successful results of these experiments show that the similar ferrites markedly differ in terms of selectivity of these transformations. While Mg−Zn selectively dehydrogenated n-butanol to butyraldehyde, Mn−Zn was a selective catalyst of the subsequent bimolecular condensation reaction of aldehydes to dipropyl ketone.…”

“…The results of temperature-programmed reduction (TPR), infrared (IR), and Brunauer−Emmett−Teller (BET) analyses are shown in the previous work. 13 The apparent helium densities of the (Mg 0.63 Zn 0.37 )-(Mn 0.1 Fe 1.8 )O 3.85 and (Mn 0.55 Zn 0.35 Fe 0.1 )Fe 2 O 4 powders were determined and understood as the material densities including the pores. To measure these densities, an Accu-Pyc 1330 V.100 helium pycnometer was used.…”

Manganese–Zinc Ferrite Synthesis by the Sol–Gel Autocombustion Method. Effect of the Precursor on the Ferrite’s Catalytic Properties

“…In this method, the temperature rapidly rises (to as much as 3000 °C) as a result of the autocombustion of the gel, which favors the formation of highly pure and crystalline products. The combustion reaction rate and amount of produced gases inhibit the grain growth and favor the synthesis of nanopowders with the developed specific surface area. − Over the past years, studies have been conducted on the synthesis of ferrites from battery scrap by the above-mentioned methods. − Nanoferrites can be used in biomedicine and cancer thermotherapy as magnetic carriers and bioseparators. − Recent studies indicate the possibility of using mixed transition-metal oxides with spinel structure as catalysts or gas sensors. − Most of the literature reports on the conversion of primary alcohols in the presence of heterogeneous catalysts are devoted to the reactions of dehydration or dehydrogenation. In the presence of particular catalysts, the bimolecular condensation of aldehydes to esters and symmetrical ketones takes place.…”