TY - JOUR
T1 - In Situ Aluminum Migration into Zeolite Framework during Methanol-To-Propylene Reaction
T2 - An Innovation to Design Superior Catalysts
AU - Li, Junjie
AU - Liu, Min
AU - Guo, Xinwen
AU - Dai, Chengyi
AU - Xu, Shutao
AU - Wei, Yingxu
AU - Liu, Zhongmin
AU - Song, Chunshan
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/6/20
Y1 - 2018/6/20
N2 - This work involves methanol-to-propylene (MTP) conversion over aluminosilicate MFI (ZSM-5), borosilicate MFI (B-ZSM-5), and all-silica MFI (Silicate-1). Both B-ZSM-5 and Silicate-1 were inactive in MTP reaction. However, extruded Silicate-1 sample prepared by extrusion with Al2O3 binder, followed by acid washing treatment, displayed a rapid increase in methanol conversion in the initial 30 h time on stream (TOS), and then retained 99% methanol conversion, higher propylene selectivity (52.2%), and higher propylene/ethylene ratio (11.3) for 400 h TOS. Silicate-1 modified with AlCl3 or Al(NO3)3 showed similar catalytic performance as the extruded samples. Several AlCl3-modified Silicate-1 samples after various TOS values were regenerated and characterized by NH3-termperature-programmed desorption (TPD), Fourier transform infrared (FT-IR) spectroscopy, and 27Al magic angle spinning nuclear magnetic responance (MAS NMR). The results point to continuous aluminum insertion into Silicate-1 framework during reaction in situ, which rationalizes the superior catalytic performance. By analyzing catalytic performances of AlCl3-modified samples with different amounts of defect sites, we concluded that Al migration is related to the defect sites. Finally, a catalyst with a much longer lifetime of 960 h and 53.2% propylene selectivity was developed by incorporating Al migration into hierarchical samples.
AB - This work involves methanol-to-propylene (MTP) conversion over aluminosilicate MFI (ZSM-5), borosilicate MFI (B-ZSM-5), and all-silica MFI (Silicate-1). Both B-ZSM-5 and Silicate-1 were inactive in MTP reaction. However, extruded Silicate-1 sample prepared by extrusion with Al2O3 binder, followed by acid washing treatment, displayed a rapid increase in methanol conversion in the initial 30 h time on stream (TOS), and then retained 99% methanol conversion, higher propylene selectivity (52.2%), and higher propylene/ethylene ratio (11.3) for 400 h TOS. Silicate-1 modified with AlCl3 or Al(NO3)3 showed similar catalytic performance as the extruded samples. Several AlCl3-modified Silicate-1 samples after various TOS values were regenerated and characterized by NH3-termperature-programmed desorption (TPD), Fourier transform infrared (FT-IR) spectroscopy, and 27Al magic angle spinning nuclear magnetic responance (MAS NMR). The results point to continuous aluminum insertion into Silicate-1 framework during reaction in situ, which rationalizes the superior catalytic performance. By analyzing catalytic performances of AlCl3-modified samples with different amounts of defect sites, we concluded that Al migration is related to the defect sites. Finally, a catalyst with a much longer lifetime of 960 h and 53.2% propylene selectivity was developed by incorporating Al migration into hierarchical samples.
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U2 - 10.1021/acs.iecr.8b00513
DO - 10.1021/acs.iecr.8b00513
M3 - Article
AN - SCOPUS:85048134884
SN - 0888-5885
VL - 57
SP - 8190
EP - 8199
JO - Industrial and Engineering Chemistry Research
JF - Industrial and Engineering Chemistry Research
IS - 24
ER -