TY - JOUR

T1 - Effect of the phase composition of Ca-Al hydroxide precursors on the mayenite formation

AU - Kapishnikov, Aleksandr V.

AU - Shuvarakova, Ekaterina I.

AU - Cherepanova, Svetlana V.

AU - Gerasimov, Evgeny Y.

AU - Bespalko, Yulia N.

AU - Maksimovskiy, Evgeny A.

AU - Volodin, Alexander M.

AU - Bedilo, Alexander F.

N1 - This research was funded by the Ministry of Science and Higher Education of the Russian Federation within the governmental assignments for Boreskov Institute of Catalysis (project FWUR-2024-0034) and for Novosibirsk State University (project FSUS-2024-0020).

PY - 2025/5/19

Y1 - 2025/5/19

N2 - Specific features of the mayenite formation from hydroxide precursors with different phase compositions as well as the evolution of the surface morphology during this process were studied. The synthesis temperature was found to have a substantial effect on the phase composition of the obtained Ca-Al hydroxide precursors with Ca:Al = 6:7 stoichiometry. Practically no reaction between calcium hydroxide and aluminum oxyhydroxide was observed at 25 °C whereas synthesis at 75 °C led to crystallization of a mixed hydroxide katoite Ca3Al2(OH)12. It was demonstrated that in the latter case the decomposition of the katoite phase at 300 °C results in the formation of the mayenite phase with the 3–4 times higher yield than in the former case. When the sample formed from katoite was calcined further at 500 °C, the mayenite average crystallite size decreased from 95 to less than 30 nm. This sample featured the highest surface area of 83 m2/g with mayenite as the predominating crystalline phase. Katoite appears to be the key intermediate in the production of finely dispersed mayenite by this method. Calcination at 600–900 °C leads to gradual mayenite sintering with the decrease of the surface area and appearance of new large pores that can be easily observed in microscopic images.

AB - Specific features of the mayenite formation from hydroxide precursors with different phase compositions as well as the evolution of the surface morphology during this process were studied. The synthesis temperature was found to have a substantial effect on the phase composition of the obtained Ca-Al hydroxide precursors with Ca:Al = 6:7 stoichiometry. Practically no reaction between calcium hydroxide and aluminum oxyhydroxide was observed at 25 °C whereas synthesis at 75 °C led to crystallization of a mixed hydroxide katoite Ca3Al2(OH)12. It was demonstrated that in the latter case the decomposition of the katoite phase at 300 °C results in the formation of the mayenite phase with the 3–4 times higher yield than in the former case. When the sample formed from katoite was calcined further at 500 °C, the mayenite average crystallite size decreased from 95 to less than 30 nm. This sample featured the highest surface area of 83 m2/g with mayenite as the predominating crystalline phase. Katoite appears to be the key intermediate in the production of finely dispersed mayenite by this method. Calcination at 600–900 °C leads to gradual mayenite sintering with the decrease of the surface area and appearance of new large pores that can be easily observed in microscopic images.

KW - A. Calcination

KW - A. powders: chemical preparation

KW - B. Porosity

KW - B. X-ray methods

KW - Mayenite

KW - A. Calcination

KW - A. powders: chemical preparation

KW - B. Porosity

KW - B. X-ray methods

KW - Mayenite

UR - https://www.mendeley.com/catalogue/412d6f0d-1897-3d4e-9308-ccf4f08bd962/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-105005511401&origin=inward&txGid=5ec78bb367e40349ad0243886fd99371

U2 - 10.1016/j.ceramint.2025.05.272

DO - 10.1016/j.ceramint.2025.05.272

M3 - статья

JO - Ceramics International

JF - Ceramics International

SN - 0272-8842

ER -