Abstract
It has been shown that the addition of triethanolamine (TEA) (22′2″-nitrilotriethanol) to zeolite Na-A synthesis gels with composition Al2O3 0.84SiO2 1.94Na2O xTEA 194H2O leads to a substantial increase in crystal size. At large TEA additions (x > 10) zeolite Na-X is produced in increasing amounts until almost pure Na-X is observed at x = 30. These observations suggest an aluminum complexing role for TEA such that the nucleation of Na-A is being suppressed. The crystallization rate of the zeolite is also inhibited by the depleted reservoir of unbound aluminum. This phenomenon gives rise to longer crystallization times and larger crystals. A second set of experiments using a reaction composition with lower aluminum content (0.7Al2O3 0.84SiO2 1.94Na2O xTEA 194H2O) showed similar trends. However, the amount of TEA required to initiate formation of zeolite Na-X in the final product was reduced relative to the first experiment.
Original language | English |
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Pages (from-to) | 363-372 |
Number of pages | 10 |
Journal | Studies in Surface Science and Catalysis |
Volume | 49 |
Issue number | C |
DOIs | |
State | Published - Jan 1 1989 |