Structural, textural and acid–base properties of carbonate-containing hydroxyapatites

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 2; no. 29; pp. 11073 - 11090
• Main Authors: Silvester, Lishil, Lamonier, Jean-Francois, Vannier, Rose-Noeelle, Lamonier, Carole, Capron, Mickaeel, Mamede, Anne-Sophie, Pourpoint, Frederique, Gervasini, Antonella, Dumeignil, Franck
• Format: Journal Article
• Language: English
• Published: Royal Society of Chemistry 01.01.2014
• Subjects: Carbonates; Catalysis; Cations; Chemical Sciences; Correlation; Hydroxyapatite; Isopropanol; Synthesis; Vacancies; X-ray photoelectron spectroscopy
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c4ta01628a

Carbonate-containing hydroxyapatites with different Ca/P ratios and optionally containing Na+ cations were successfully synthesized using a precipitation method. The solids were extensively characterized by XRD, LEIS, XPS, IR, TGA and NMR. Further, their acid-base properties were determined by NH3-TPD, PEA-XPS, CO2-TPD and by pulsed liquid chromatography using benzoic acid as a probe. The so-obtained structural, textural and acid-base properties could be finely correlated to give a clear picture of the system. The acidic properties of hydroxyapatites were attributed to Ca2+, surface HPO42- and OH- vacancies and the basic properties were attributed to PO43-, OH- and CaO species. The fine-tuning of the amount, of the nature and the strength of acid-base properties derived by varying the carbonate content in hydroxyapatites can find applications in catalysis, which was illustrated by isopropanol reactivity.