TY - JOUR
T1 - Incorporation of Al3+ ions to promote the stabilization effect of (NH4)2SiF6 treatment on the hydrothermal stability of mesoporous SBA-15 zeolite
AU - Zou, Chenglong
AU - Sha, Guanyu
AU - Huang, Yao
AU - Niu, Guoxing
AU - Zhao, Dongyuan
PY - 2015/7
Y1 - 2015/7
N2 - This work demonstrates an improved (NH4)2SiF6 treatment to enhance the hydrothermal stability of mesoporous SBA-15 zeolite. In this treatment, Al3+ ions are incorporated into SBA-15 zeolite first, then it is treated with 5 (NH4)2SiF6 solution according to 1 SiO2 of SBA-15 and finally washed with HCl (2 mol/L) to remove the pre-incorporated Al3+ ions. The obtained SBA-15 exhibits higher hydrothermal stability than that without pre-incorporated Al3+. Compared with the latter, the sample maintains a better ordered mesostructure and a larger surface area (271 m2/g) after hydrothermal treatment at 800 ?C for 12 h in 100 steam. The results show that incorporating Al3+ ions into SBA-15 zeolite before (NH4)2SiF6 treatment obviously promotes the stabilization effect of (NH4)2SiF6 treatment. The mechanism suggests that the incorporated Al3+ ions can effectively capture F- ions that have been released from (NH4)2SiF6, and thus reduce their etching into the SBA-15 zeolite framework. This ensures that the positive factors of (NH4)2SiF6 treatment, such as silicon insertion and surface hydrophobization by F- ions, play effective roles in the improvement of the hydrothermal stability of SBA-15 zeolite. This promoting effect of the Al3+ ions is closely related to the method that is used to introduce the Al3+ and the SBA-15 zeolite processing temperature
AB - This work demonstrates an improved (NH4)2SiF6 treatment to enhance the hydrothermal stability of mesoporous SBA-15 zeolite. In this treatment, Al3+ ions are incorporated into SBA-15 zeolite first, then it is treated with 5 (NH4)2SiF6 solution according to 1 SiO2 of SBA-15 and finally washed with HCl (2 mol/L) to remove the pre-incorporated Al3+ ions. The obtained SBA-15 exhibits higher hydrothermal stability than that without pre-incorporated Al3+. Compared with the latter, the sample maintains a better ordered mesostructure and a larger surface area (271 m2/g) after hydrothermal treatment at 800 ?C for 12 h in 100 steam. The results show that incorporating Al3+ ions into SBA-15 zeolite before (NH4)2SiF6 treatment obviously promotes the stabilization effect of (NH4)2SiF6 treatment. The mechanism suggests that the incorporated Al3+ ions can effectively capture F- ions that have been released from (NH4)2SiF6, and thus reduce their etching into the SBA-15 zeolite framework. This ensures that the positive factors of (NH4)2SiF6 treatment, such as silicon insertion and surface hydrophobization by F- ions, play effective roles in the improvement of the hydrothermal stability of SBA-15 zeolite. This promoting effect of the Al3+ ions is closely related to the method that is used to introduce the Al3+ and the SBA-15 zeolite processing temperature
U2 - 10.1016/S1872-2067(15)60855-5
DO - 10.1016/S1872-2067(15)60855-5
M3 - Article
SN - 0253-9837
VL - 36
SP - 1001
EP - 1008
JO - Chinese Journal of Catalysis
JF - Chinese Journal of Catalysis
IS - 7
ER -