TY - JOUR
T1 - 2D versus 3D MFI zeolite
T2 - The effect of Si/Al ratio on the accessibility of acid sites and catalytic performance
AU - Wei, Ruicong
AU - Yang, Hong
AU - Scott, Jason Anthony
AU - Aguey-Zinsou, Kondo Francois
AU - Zhang, Dongke
PY - 2018/6/1
Y1 - 2018/6/1
N2 - Through the synthesis of 2D MFI zeolite samples of Si/Al ratio ranged from 13 to 74 with inter-crystalline mesoporosity and their reference 3D counterparts, we have systematically studied and revealed the impact of Si/Al ratio on the inter-dependence of core intrinsic properties of structural porosity and acidity. It is apparent that mesopores in the 2D MFI zeolite play a critical role, dictating the accessibility and distribution of specific acid sites. It was found that, compared to their 3D counterparts, the 2D samples possess a three-times larger accessible surface area owing to the mesopores. Although having a slightly lower total number of acid sites, the 2D samples enjoy a higher percentage of accessible strong acid sites and weak Lewis acid sites. Consequently, in three selected liquid phase reactions, which had different acidity demands and molecular diffusion constraints, the 2D samples demonstrated much higher catalytic activities and resistance to deactivation. This study has, for the first time, established the relationship between Si/Al ratio and acidity for the 2D MFI zeolite, thus enabling rational selection of a Si/Al ratio for a targeted application.
AB - Through the synthesis of 2D MFI zeolite samples of Si/Al ratio ranged from 13 to 74 with inter-crystalline mesoporosity and their reference 3D counterparts, we have systematically studied and revealed the impact of Si/Al ratio on the inter-dependence of core intrinsic properties of structural porosity and acidity. It is apparent that mesopores in the 2D MFI zeolite play a critical role, dictating the accessibility and distribution of specific acid sites. It was found that, compared to their 3D counterparts, the 2D samples possess a three-times larger accessible surface area owing to the mesopores. Although having a slightly lower total number of acid sites, the 2D samples enjoy a higher percentage of accessible strong acid sites and weak Lewis acid sites. Consequently, in three selected liquid phase reactions, which had different acidity demands and molecular diffusion constraints, the 2D samples demonstrated much higher catalytic activities and resistance to deactivation. This study has, for the first time, established the relationship between Si/Al ratio and acidity for the 2D MFI zeolite, thus enabling rational selection of a Si/Al ratio for a targeted application.
KW - 2D MFI zeolite
KW - Acidity
KW - Catalytic activity
KW - Diffusion
KW - Si/Al ratio
UR - http://www.scopus.com/inward/record.url?scp=85041579923&partnerID=8YFLogxK
U2 - 10.1016/j.mtchem.2018.01.002
DO - 10.1016/j.mtchem.2018.01.002
M3 - Article
AN - SCOPUS:85041579923
VL - 8
SP - 1
EP - 12
JO - Materials Today Chemistry
JF - Materials Today Chemistry
SN - 2468-5194
ER -