TY - JOUR
T1 - Thermochemical study of the structural stability of low-silicate CHA zeolite crystals
AU - Taherizadeh, Alireza
AU - Harpf, Anja
AU - Simon, Adrian
AU - Choi, Jungkyu
AU - Richter, Hannes
AU - Voigt, Ingolf
AU - Stelter, Michael
N1 - Funding Information:
This work was performed within the framework of an ZeoUp project (FKZ:01DR17015A) and sponsored by Federal Ministry of Education and Research.
Publisher Copyright:
© 2022 The Authors
PY - 2022/1
Y1 - 2022/1
N2 - In this study, the effect of synthesis method on the structural stability of low-silica CHA zeolite crystals were investigated. For this purpose, template-free CHA crystals with similar chemical compositions were synthesized using seeded secondary growth and inter-zeolite transformation approaches. The stability performance of as-synthesized crystals was studied at temperatures, steam flow in a closed system, and acidic media. The results were analyzed using XRD, FTIR, DLS and FESEM. It was found both methods have similar structural stability behavior. The thermal stability investigation proved they have maintained their crystalline structure against heating, up to 800 °C, and at higher temperatures, the amorphous phase prevailed. The CHA crystals synthesized via both methods are stable in terms of hydrothermal stability up to 200 °C. Moreover, the results of chemical resistance showed CHA crystals exhibit excellent resistance to weak acidic medium, but against stronger acids, it has completely lost its crystallinity after 72 h.
AB - In this study, the effect of synthesis method on the structural stability of low-silica CHA zeolite crystals were investigated. For this purpose, template-free CHA crystals with similar chemical compositions were synthesized using seeded secondary growth and inter-zeolite transformation approaches. The stability performance of as-synthesized crystals was studied at temperatures, steam flow in a closed system, and acidic media. The results were analyzed using XRD, FTIR, DLS and FESEM. It was found both methods have similar structural stability behavior. The thermal stability investigation proved they have maintained their crystalline structure against heating, up to 800 °C, and at higher temperatures, the amorphous phase prevailed. The CHA crystals synthesized via both methods are stable in terms of hydrothermal stability up to 200 °C. Moreover, the results of chemical resistance showed CHA crystals exhibit excellent resistance to weak acidic medium, but against stronger acids, it has completely lost its crystallinity after 72 h.
KW - Catalysts
KW - Inter-zeolite transformation
KW - Low-silica CHA
KW - Seeded secondary growth
KW - Structural stability
UR - http://www.scopus.com/inward/record.url?scp=85135870495&partnerID=8YFLogxK
U2 - 10.1016/j.rechem.2022.100466
DO - 10.1016/j.rechem.2022.100466
M3 - Article
AN - SCOPUS:85135870495
SN - 2211-7156
VL - 4
JO - Results in Chemistry
JF - Results in Chemistry
M1 - 100466
ER -