Stable extra-large-pore zeolites are desirable for industrial purposes due to their ability to accommodate bulky reactants and diffusion through channels. Although there are several extra-large pore zeolites reported, stable ones are rare. Thus, their stabilization is a feasible strategy for industrial applications. Here, an extra-large-pore zeolite EWT with boron substitution is presented, and the resulting zeolite B-RZM-3 increased the thermal stability from 600 °C in its silica form to 850 °C. The crystal structure, determined by combining continuous rotation electron diffraction (cRED) and powder X-ray diffraction (PXRD), shows that B atoms preferentially substitute the interrupted (HO)T(OT) 3 (Q 3 ) sites and are partially converted into 3-coordination to relax framework deformation upon heating. After Al-reinsertion post-treatment, Al-B-RZM-3 shows higher ethylbenzene selectivity and ethylene conversion rate per mol acid site than commercial ZSM-5 and Beta zeolite in benzene alkylation reaction. Synthesizing extra-large-pore zeolite in borosilicate form is a potential approach to stabilize interrupted zeolites for commercial applications.
IM-5 zeolite modified by H2SiF6 has superior activity, equivalent stability, higher DEB selectivity and a lower xylene selectivity in comparison of ZSM-5 with similar Si/Al2 ratio. The process provides a new way to make ethylbenzene in the vapor phase.
The effects of the zeolite structure and acidic property on the activity and selectivity in gas‐phase alkylation of benzene with ethylene were investigated using TUN, IMF, *SFV and MFI with different structures and Si/Al2 ratios. The channels of TUN and IMF provide both higher selectivity to ethylation (ethylbenzene and di‐ethylbenzene) and lower xylene selectivity compared to MFI with slightly smaller pore diameter in which the pore diffusion limitations are suffered. The activity is mainly controlled by zeolite channel architecture. The higher activity and selectivity are obtained using modified TUN and modified IMF with suitable density of Brønsted acidity in a well‐defined channel structure sterically constrained for heavy by‐products. It is shown that the activity and selectivity increase with increasing pore diameter of three‐dimensional 10 ring channel structure, while the rule is not valid for *SFV.
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