Catalysts based on transition metals have been of particular interest in various fields of science for some time now. They are used in pharmaceuticals, natural products, chemicals, aromatic hydrocarbon hydrogenation, etc. An essential property of this type of catalysts is environmental friendliness and reusability. The most commonly used transition metal catalysts are rhodium, palladium, ruthenium, copper, nickel, and iron. Hydroxyapatite has recently been added to this list.
Hydroxyapatite (Ca10 (PO4) 6 (OH) 2, HAp), doped with various transition metals, is of great interest to scientists at Kazan Federal University in the context of its application in various fields. Also, hydroxyapatite is considered as a catalyst with a number of attractive properties. As the scientists explain, the paper contains a comprehensive analysis of the introduction of iron (II) and (III) into the HAp lattice using density functional theory (DFT) calculations.
"In this work, we consider the possible positions of the replacement of calcium ions by iron ions in hydroxyapatite. From the calculations, we obtain information about the positions in which impurity centers are most likely to sit, what happens with the structure, with the local environment, what bonds are formed in this case," says co-author Daria Shurtakova, Engineer at KFU's Laboratory of Magnetic Radio Spectroscopy and Quantum Electronics.
Scientists showed that the incorporation of Fe2+ in the Ca (1) and Ca (2) positions of HAp is energetically comparable, while Fe3+ is preferentially localized in the Ca (2) position.
Source: https://eng.kpfu.ru/