Thermally Induced Phase Transformation of Mn - LTA and Mn-FAU Zeolite to Anorthite Phases

Abstract

Data on thermally induced transformations of Mn exchanged zeolites LTA and FAU topology are presented in this paper. Thermally induced phase transformation of Mn-exchange zeolites are followed in the range from 700 to 1300 degrees C. Both frameworks collapse into amorphous intermediate products after heating between 600 and 650 degrees C. Prolonged heating of the intermediate product above 1100 degrees C results directly in formation of a disorder Mn-anorthite LTA and Mn-anorthite(FAU). The parameter of unit cell of Mn-anorthite(LTA) and Mn-anorthite(FAU), in temperature range between 700 and 1300 degrees C, was observed in space group C1. The phase conversions in the temperature range investigated were followed by thermal, Xray powder diffraction and FT-IR analyses.