Effect of the Mg:Al Ratio on Borate (or Silicate)/Nitrate Exchange in Hydrotalcite

✍ Scribed by M. del Arco; S. Gutiérrez; C. Martı́n; V. Rives; J. Rocha

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 212 KB
• Volume: 151
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2000.8653

✦ Synopsis

Layered double hydroxides (LDHs) have been prepared with interlayer nitrate and with di4erent Mg : Al ratios. Solids with low Mg : Al ratios show larger basal spacings than those with larger Mg : Al ratios, consistent with tilting of the nitrate ions, respectively. Nitrate/tetraborate and nitrate/silicate anionic exchange has been achieved only for those samples with 99tilted:: nitrate. The precise nature of the interlayer species in the exchanged samples has been concluded from MAS+NMR results. The layered structure of the exchanged samples collapses at temperatures higher than those for the nitrate-containing precursors.