Investigations of TsVM zeolite acidities with different degrees of exchange of Na+ by H+
1987
The method of programmed thermal desorption of ammonia has been used to establish that on the surface of the sodium form of type TsVM zeolite having a modulus SiO2/Al2O3= 34.5 there are two types of acidic centers having ammonia desorption activation energies Ed equal to 40–45 and 80–100 kJ/mole. Replacement of Na+ by H+ leads to the appearance of a third type of center with a value ED=130–150 kJ/mole. In this case in the IR spectra of specimens saturated with ammonia a band appears at 1410 cm−1, which is evidence for the presence of NH 4 + ions. Increasing the degree of Na+ replacement by H+ leads to a nonproportional rapid increase in the concentration of highly energetic centers, which may be explained by the partial transfer of aluminum into cationic positions with the formation of additional acidic centers.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
6
References
0
Citations
NaN
KQI