Alkali Treatment of Commercial Silicoaluminophosphate Molecular Sieves (SAPO<sub>-</sub>34) Enhances the Water Adsorption and Desorption Properties

• 作者: Ayaka Satoh Kota Aoyagi Kota Horiuchi Masahiro Katoh Shigeru Sugiyama
• 来源期刊: 封装与吸附期刊(英文)
• 学科: 化学
• 关键词: Alkali Treatment SILICOALUMINOPHOSPHATE Molecular SIEVES WATER Adsorption Desorption
• 年，卷（期）: 2019,（4）
• 页码范围: 149-158
• 页数: 10页
• 分类号: O64

摘要

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.