Syntheses and surface properties determination of the ammonium, methylamine and ethilamine phases of cerium (IV) and thorium (IV) phosphates

Abstract

The characterization of solid phases formed by Sorption of ammonia, methylamine and ethylamine on cerium (IV) and thorium (IV) hydrogen phosphates is reported in this paper. Separate samples of both phosphates, dried at 110°C and evacuated under a dynamic vacuum, were allowed to adsorb NH 3, CH 3-NH 2 and CH 3-CH 2-NH 2 into a gravimetric adsorption device until equilibrium was reached. X-ray diffraction patterns of the treated samples showed that retention of methylamine and ethylamine by cerium and thorium phosphates causes the interlayer spacing to expand. At the same time, in the corresponding IR spectra bands appear characteristic of the NH + 4 and R-NH + 3 groups formed by protonation of ammonia and alkilamines sorbed molecules. N 2 adsorption isotherms of the materials show that surface area available for the N 2 molecules is not sensitive to amine retention, while the surface acidity decreases strongly.