Role of hydrophobic effects in organic reactions catalysed by zeolites

✍ Scribed by Annie Finiels; Patrick Geneste; Jérôme Lecomte; Frédérique Marichez; Claude Moreau; Patrice Moreau

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 123 KB
• Volume: 148
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/s1381-1169(99)00046-1

✦ Synopsis

The role of hydrophobic effects of dealuminated mordenites SirAl ratios varying from 7 to 100 has been investigated in two reactions carried out in aqueousralcoholic media: hydroxymethylation of furfuryl alcohol with aqueous formaldehyde Ž . and hydration of phenyl-acetylene in alcohol medium. For both reactions, initial rates and turn over frequencies TOF increase in a significant extent with increasing SirAl ratios. It is shown that the differences thus observed in the TOF values are characteristic of variations in the hydrophobicity of the various dealuminated mordenites, which is confirmed by the corresponding increase of the hydrophobicity parameter h, determined by thermogravimetric analysis of such samples. The hydrophobic character of the zeolites is also discussed in terms of the softness and activity of the corresponding Bronsted äcid sites.