IR-spectroscopic research of natural zeolites and their lanthanus-containing forms
Abstract
Using IR spectroscopy, natural samples of analcime, mesolite, stilbite, chabazite, scolecite and their La-substituted forms were studied. The sorption of lanthanum ions by monominerals of zeolites caused a shift in the absorption bands in the region of the characteristic deformation vibrations inside the tetrahedra in the spectra of stilbit, chabasite and mesolite. It is assumed that the shift of the absorption bands is due to the
perturbation of the zeolite framework by electrostatic interactions with lanthanum ions. It was revealed that the absorption bands are shifted in the region of oscillations of the structural groups of the alumino-siliconoxygen skeleton. A rather noticeable shift of frequencies from 707 to 714 cm-1 occurred in the region of intratetrahedral symmetric stretching vibrations in the stilbit spectrum. The shift of the absorption bands in
the region of oscillations 650-820 cm-1 indicates a partial removal of aluminum. The shift of the absorption bands in this region also occurred in the spectra of the Mesolithic, scolecite. The appearance of a new absorption band at 953 cm-1 in the stilbite spectrum and a shift in the absorption band from 939 cm-1 to 932 cm-1 in the spectrum of the Mesolithic in the region of vibrations of the Al-OH bond, possibly due to the sorption of lanthanum ions with the formation of new La - bonds About with oxygen scaffold. The sorption of lanthanum ions on the mineral forms of zeolites — scolecite, analcime, mesolite, stilbite — causes a decrease in the excess negative charge of the skeleton of zeolites as a result of compensation by the positive ions of the rareearth metal. Thus, the sorption of lanthanum ions occurs at the surface centers of the zeolite, which have undergone partial dealumination, with the formation of new La – O bonds with the oxygen of the framework. In addition, the lanthanum ion forms a bond with the oxygen of hydroxyl groups localized either in small cavities, hexagonal prisms or sodalite cells of the zeolite.
Downloads
References
2. Brek D. Ceolitovye molekulyarnye sita. M., Mir, 1976, 781 p.
3. Boldyrev A.I. Infrakrasnye spektry mineralov. M., Nedra, 1976, 199 p.
4. Gorohov V.K. Ceolity Sahalina. Vladivostok, Dal'nevost. kn. izd-vo, 1982, 108 p.
5. Trohimec A.I., ZHurnal fizicheskoj himii, 1997, Vol. 71, No 11, pp. 2013.
6. Himiya ceolitov i kataliz na ceolitah / Pod red. Dzh. Rabo. T.1. M., Mir, 1980, 506 p.
7. Ul'yanova N.Yu. Diss. kand. him. nauk. Sankt-Peterburg, 2016, 139 p.
8. Dampilova B.V., Zonhoeva EH.L., ZHurnal fizicheskoj himii, 2013, Vol. 87, No 8, pp. 1361-1366.
9. Dampilova B.V., Zonhoeva EH.L., Sorbcionnye i khromatograficheskie protsessy, 2012. 2012, Vol. 12, No 3, pp. 439-444.
10. Zonhoeva EH.L., Dampilova B.V., Sorbcionnye i khromatograficheskie protsessy, 2017, Vol. 17, No 5, pp. 916 -922.
11. Ceolitonosnost' bazal'tov Zabajkal'ya / Pod red. Andreeva G.V. Novosibirsk, Nauka, sib. Otd-nie, 1989, 96 p.
12. CHelishchev N.F., Volodin V.F., Kryukov V.L. Ionoobmennye svojstva prirodnyh vysokokremnistyh ceolitov. M., Nauka, 1988, 128 p.
13. Rakitskaya T.L., Vіsnik ONU. Khіmіya, 2015, Vol. 20, No 2 (54). pp. 6-15. Rezhim dostupa: http://dx.doi.org/10.18524/2304-
0947.2015.2(54).5062414. Makarov A.V. Diss. Kand. Tekhn. nauk. Tomsk, 2013.17 p.
15. Kosheleva L.S., Izvestiya Akademii nauk. Seriya khimicheskaya, 1994, No 3, pp. 387-391.
