FTIR and Thermogravimetric Study of Silicalite Treated with Methanol

Abstract

FTIR and TGA-DTA techniques were used for the high-defective Al-Na free silicalite characterization. Methanol reacting with external and internal silanols provides a sample modification evidenced by the combined use of these two techniques. A quantitative correlation between the FTIR and TGA data was drawn out although the incomplete methoxylation did not allow to quantify the total number of silanols. At least two distinct types of methoxylated sites were found according to their oxidation temperature which is unexpectedly high for one of them.