TY - JOUR
T1 - Combined desilication and phosphorus modification for high-silica ZSM-5 zeolite with related study of hydrocarbon cracking performance
AU - Ding, Jian
AU - Wang, Meng
AU - Peng, Luming
AU - Xue, Nianhua
AU - Wang, Yimeng
AU - He, Ming Yuan
N1 - Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/7/25
Y1 - 2015/7/25
N2 - Mesoporosity was introduced into high-silica ZSM-5 zeolite (SiO2/Al2O3 = 417) by controlled desilication using the mixture of NaOH and TEAOH (tetraethylammonium hydroxide), and subsequent phosphorus modification was used to improve the structural stability and acidity reservation of the desilicated ZSM-5 samples during the procedure of severe steam aging treatment. The phosphorus modified mesoporous ZSM-5 sample along with parent ZSM-5, solo phosphorus modified ZSM-5 and mesoporous ZSM-5 were characterized by techniques of N2 adsorption-desorption, NH3-TPD (temperature programmed desorption), IR (infrared) spectroscopy of pyridine adsorption and 27Al & 31P MAS NMR spectroscopy. A mechanism for underlying chemistry of the combinative treatment was proposed. The aluminophosphate formed in the steam activation could interact with the framework aluminum on zeolite, thus achieved to the textural and acidity stabilization during the steam aging. The catalytic performance of these samples was tested by different hydrocarbon cracking reactions. It turned out that owing to its reduced diffusion limitation and stabilized acidity, the phosphorus modified mesoporous ZSM-5 sample exhibited the highest conversion in the bulky molecule cracking reaction. And in the 1-octene cracking reaction under harsh reaction conditions, the steamed phosphorus modified mesoporous ZSM-5 sample exhibited higher activity and more prolonged catalyst life compared to the other steamed catalysts, which could be attributed to the improved coke tolerance capability by mesoporosity introduction and the stabilized acid sites by phosphorus modification.
AB - Mesoporosity was introduced into high-silica ZSM-5 zeolite (SiO2/Al2O3 = 417) by controlled desilication using the mixture of NaOH and TEAOH (tetraethylammonium hydroxide), and subsequent phosphorus modification was used to improve the structural stability and acidity reservation of the desilicated ZSM-5 samples during the procedure of severe steam aging treatment. The phosphorus modified mesoporous ZSM-5 sample along with parent ZSM-5, solo phosphorus modified ZSM-5 and mesoporous ZSM-5 were characterized by techniques of N2 adsorption-desorption, NH3-TPD (temperature programmed desorption), IR (infrared) spectroscopy of pyridine adsorption and 27Al & 31P MAS NMR spectroscopy. A mechanism for underlying chemistry of the combinative treatment was proposed. The aluminophosphate formed in the steam activation could interact with the framework aluminum on zeolite, thus achieved to the textural and acidity stabilization during the steam aging. The catalytic performance of these samples was tested by different hydrocarbon cracking reactions. It turned out that owing to its reduced diffusion limitation and stabilized acidity, the phosphorus modified mesoporous ZSM-5 sample exhibited the highest conversion in the bulky molecule cracking reaction. And in the 1-octene cracking reaction under harsh reaction conditions, the steamed phosphorus modified mesoporous ZSM-5 sample exhibited higher activity and more prolonged catalyst life compared to the other steamed catalysts, which could be attributed to the improved coke tolerance capability by mesoporosity introduction and the stabilized acid sites by phosphorus modification.
KW - Desilication
KW - Hydrocarbon cracking
KW - Hydrothermal stability
KW - Mesoporous ZSM-5
KW - Phosphorus modification
UR - https://www.scopus.com/pages/publications/84937800345
U2 - 10.1016/j.apcata.2015.07.011
DO - 10.1016/j.apcata.2015.07.011
M3 - 文章
AN - SCOPUS:84937800345
SN - 0926-860X
VL - 503
SP - 147
EP - 155
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
ER -