Fluorided mordenite

Table 2 Benzene alkylation with 1-dodecene, fluorided mordenite catalysts.

The fluoride-treated acidic mordenite catalysts have, in fact, the triple advantages of ... 

The following example illustrates the preparation of a hydrogen fluoride-modified mordenite ... 

To a 500 g sample of acidic, dealuminized mordenite (CBV-20A from PQ Corporation, 1.5 mm diameter extrudates that had been calcined at 540 °C, overnight) was added a solution of 33 ml of 48% HF in 1633 ml of distilled water, and the mix cooled in ice, stirred on a rotary evaporator overnight, then filtered to recover the extruded solids. The extrudates were further washed with distilled water, dried in vacuo at 100 °C, and then calcined at 540 °C, overnight. Analyses of the treated mordenite showed 1.2% fluoride, 0.49 meq/g acidity. Samples were charged to the reactive distillation unit either as 20/40 mesh granules, or as ca. 1.5 mm extrudates. 

Figure 2 also includes a comparative experiment, where the solid acid catalyst is a sample of non-fluorided (but calcined), acidic mordenite. Here we see a) a significant loss of alkylation activity with time on stream and b) a measurably lower... 

Performances of these acidic mordenite zeolites have been examined as a function of the level of fluoride treatment. For mordenites treated with HF to fluoride levels of 0.25, 0.5, and 1.0%, batch alkylation at ca. 80 °C of typical benzene/l-dodecene mixtures show (after 1 hr) very similar levels of activity and 2-... 

Historically, the earliest C8 aromatic isomerization catalysts tended to use amorphous supports with a halogen such as chloride or fluoride. Due to water sensitivity and corrosion issues, these were replaced by large-pore zeolites such as mordenite. The larger pore size was more favorable toward bimolecular transalkylation, whereas the chlorided alumina support tended to promote cracking. In both... 

High-silica mordenite with a molar ratio of silica to aluminum (SAR) up to 30 was synthesized from a dry gel without any organic stmcture-directing agents and fluoride [06W1]. The siliceous mordenites were obtained by a dealumination treatment [92C2, 95W1]. 

The effect of the initial Si/Al ratio was studied with mordenite (Si/Al=S and 10) and Y zeolite (Si/Al=2.7 and 7). The effect of the synthesis conditions was studied in the case of Beta zeolite synthesized in alkaline and fluoride medium. The specific effect of the crystallographic structure will be deduced frmn the two first approaches and from literature data. 

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