Browsing by Subject "1,2,4-Trimethylbenzene"
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- ItemRestrictedEffects of in-situ chemical vapour deposition using tetraethoxysilane on the catalytic and sorption properties of ZSM-5.(Elsevier, 1998) Röger, H; Krämer, M; Möller, K; O'Connor, CThe external surface of HZSM-5 crystals was gradually modified by in-situ CVD of tetraethoxysilane. Using the particular procedures described in the paper, it was shown from probe reactions in combination with sorption studies that the external surface was deactivated and the pore-opening size was reduced while the intracrystalline pore space remained unmodified. The positive effect of the CVD treatment procedure on the shape selective properties of HZSM-5 was demonstrated by an enhancement in p-selectivity during toluene disproportionation. The paper discusses the relation between the effects of the CVD treatment procedure on catalytic properties, sorption properties and structural properties and conclusions are made on the use of the conversion of 1,2,4-trimethylbenzene, 1,3,5-triisopropylbenzene, toluene and n-hexane, respectively, to probe the effects of external surface modifications on properties of ZSM-5.
- ItemOpen AccessThe transformation of 1,2,4-trimethylbenzene A probe reaction to monitor external surface modifications of HZSM-5?(Elsevier, 1997) Röger, H P; Möller. K P; O'Connor, C TThe transformation of 1,2,4-trimethylbenzene is proposed as a new probe reaction to monitor the catalytic effects of inertisation of the external surface of HZSM-5. The external surface has been modified by coating ZSM-5 crystallites with an inert silicalite shell. At 723 K and a WHSV of 0.6 h−1 it has been shown that the isomerisation products 1,2,3-trimethylbenzene and 1,3,5-trimethylbenzene reflect changes in external activity. The disproportionation products, 1,2,4,5-tetramethylbenzene and 1,2,3,5-tetramethylbenzene together are shown to indicate changes in overall activity and shape selective properties of the catalyst sample. The results correlate with those observed for the reaction of 1,3,5-triisopropylbenzene and n-hexane cracking.