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 JEAS  Vol.9 No.4 , December 2019
Alkali Treatment of Commercial Silicoaluminophosphate Molecular Sieves (SAPO-34) Enhances the Water Adsorption and Desorption Properties
Abstract: Commercial silicoaluminophosphate molecular sieves (SAPO-34) received alkali treatment with either NaOH (0.2, 0.01, 0.005, or 0.001 M) or NH4OH (0.005 M). Treatment with NaOH (0.005 M) increased the water adsorption initial rate of SAPO-34 by 1.4-fold. The alkali treatment introduced Na+ adsorption sites into the SAPO-34. The desorption ratio (adsorption at 30°C and desorption at 100°C) was 88.2% higher than the original rate (84.3%). On the other hand, after alkali treatment of SAPO-34 using NH4OH (0.005 M), calcination resulted in the highest desorption ratio at 91.3%. When combined with calcination, alkali treatment with NH4OH introduced H+adsorption sites into SAPO-34, H+ adsorption sites feature low levels of interaction with water, which enhanced the desorption ratio, but decreased the initial adsorption rate. These results indicate that treating commercial SAPO-34 with 0.005 M NaOH enhances both the adsorption and desorption behaviors.
Cite this paper: Katoh, M. , Horiuchi, K. , Satoh, A. , Aoyagi, K. and Sugiyama, S. (2019) Alkali Treatment of Commercial Silicoaluminophosphate Molecular Sieves (SAPO-34) Enhances the Water Adsorption and Desorption Properties. Journal of Encapsulation and Adsorption Sciences, 9, 149-158. doi: 10.4236/jeas.2019.94008.
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