Synthesis, Characterization, and1H and71Ga MAS NMR Spectroscopy of a Novel Mg/Ga Double Layered Hydroxide

✍ Scribed by Marı́a Angeles Aramendı́a; Victor Borau; César Jiménez; José Maria Marinas; Francisco José Romero; José Rafael Ruiz

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 272 KB
• Volume: 131
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1997.7347

✦ Synopsis

A new brucite-like layered Mg/Ga double hydroxide (LDH) of composition [Mg 0.174 Ga 0.256 (OH) 2 ] (CO 3 ) 0.134 • mH 2 O was synthesized by coprecipitation at pH 10. The hydroxide and the mixed oxides resulting from its thermal decomposition at 523, 823 and 1073 K were characterized by X-ray diffraction, diffuse reflectance infrared spectroscopy, high-resolution solid-state nuclear magnetic resonance (MAS NMR), and thermogravimetric analysis. The surface properties of the solid (specific surface) and its basicity were also determined. The Mg/Ga LDH was found to be stable up to 523 K and to decompose into a mixture of periclase MgO and amorphous Ga 2 O 3 at 823 K. Its changes with temperature were monitored by using 1 H and 71 Ga MAS NMR; 1 H MAS NMR spectra revealed the loss of interlayer OH groups supporting the brucite-like structure on calcination at 823 K.