20 октомври 2021
Velinov, N., Petrova, T., Ivanova, R., Tsoncheva, T., Kovacheva, D., Eliyas, A., Mitov, I..
(
Александър Елияс;
Николай Велинов;
Таня Петрова;
)
Abstract
Materials with cation ratio Cu:Ni:Fe?=?0.5:0.5:2 were prepared by sol-gel auto-combustion technique using corresponding metal nitrates and citric acid as complexating/fuel agent and ammonia for pH adjustment. For comparison, one sample was synthesised by the same method, but without pH adjustment, and one sample with nominal composition Cu0.5Ni0.5Fe2O4 was synthesised by co-precipitation method. The methods of X-Ray Diffraction, M?ssbauer spectroscopy at room (RT) and liquid nitrogen (LNT) temperature, UV-Vis, FTIR, nitrogen physisorption, and H2-TPR were applied for structural characterization of the materials. X-Ray Diffraction and M?ssbauer spectroscopy proved formation of spinel phase, Fe4-xNixN and minor quantity CuO phase. Presence of doublets with high quadrupole splitting (??=?1.02–1.07 mm/s) at RT M?ssbauer spectra, which are partly preserved at LNT is evidenced that nitride phase has high nickel content. Specific surface of oxide/nitride samples was determined in the range 19–24 m2/g. The catalytic behaviour of the Cu-Ni-Fe- oxide/nitride materials is studied in reaction of methanol decomposition. M?ssbauer spectra reveal significant phase transformations of the samples to H?gg carbide (?-Fe5C2) and Fe,Ni-alloy under the reaction medium, which ensures good catalytic activity and selectivity to H2 and CO. The photocatalytic oxidation activity of samples was tested in degradation of Alizarin model contaminant dissolved in water under visible light and UV-C light irradiation.
Hyperfine Interactions, 242, 10, Springer, 2021, DOI:doi.org/10.1007/s10751-021-01742-6, 1-14. SJR (Scopus):0.359 Q3 (Scopus)
https://doi.org/10.1007/s10751-021-01742-6
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