Year of publication
2013
Journal
Journal of Catalysis
Volume
300
Starting page
235
Ending page
241
The acidic zeolite H-ZSM-5 is a widely used catalyst in industrial methanol-to-hydrocarbons (MTH) con- version, due to its pronounced stability to the formation of unreactive arenes that degrade the catalyst. In the present work, adsorption of a series of mono- and polycyclic arenes in H-ZSM-5 is modeled through periodic density functional theory calculations on the complete unit cell employing the BEEF-vdW func- tional. Polycyclic arenes are predicted to fit in the zeolite framework, the preferred adsorption site being the intersection region between the straight and sinusoidal channels. Supporting recent experimental results, an adsorbate orientation along the straight channel is predicted. A pronounced confinement of the arenes governs their directional interaction with acid sites. From the findings, it is plausible that deac- tivation of H-ZSM-5 during MTH conversion is caused by polycyclic arenes growing in the straight chan- nels near the outer surface of the zeolite crystal on which they join to form graphitic layers.
Keywords
zsm-5; silicalite-1; methanol-to-hydrocarbons conversion; catalyst deactivation; density functional theory; van der waals interaction; hydrogen bonding; host-guest interaction; adsorption; zeolite-catalyzed methylation; chemical accuracy; olefin catalysis; molecular-sieves; coke formation; hydrogen-bond; n-alkanes; conversion; adsorption; benzene
Research Areas
Funding sources
SUNCAT People