Characterization by XRD, DRIFT, and MAS NMR Spectroscopies of a Mg2P2O7Catalyst

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

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 120 KB
• Volume: 202
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1998.5465

✦ Synopsis

which they used in the dehydration of isopropyl alcohol. The The dehydration-dehydrogenation of 2-hexanol in the presence IR bands for adsorbed pyridine observed at 1445 and 1610 of a catalyst obtained from magnesium hydrogen phosphate was cm 01 suggested the presence of Lewis acid sites, to which studied. The catalyst activity was found to be related to the nature they assigned a prominent role in the dehydration process of surface OH sites. Examination of the catalyst by the XRD, DRIFT, because they found catalysts calcined above 973 K to preserve 1 H and 31 P MAS NMR, and UV-visible absorption techniques alsome activity. This was the likely result of Ni-O or P-Olowed the nature of the catalytically active sites to be established and P electron-deficient sites, which play an active role in dehythe catalytic activity results to be explained. ᭧ 1998 Academic Press dration, being formed at those temperatures. The result is an Key Words: 1 H and 31 P MAS NMR; dehydation-dehydrogenaincreased surface basic character that stems from the reartion; 2-hexanol. rangement produced by a change in Ni symmetry and the removal of surface OH groups. In recent years, high-resolution solid-state NMR spectros-EXPERIMENTAL tivity must be exerted by this type of site. Malinowski et al. (18) prepared various nickel and nickel-calcium phosphates, Materials We used a commercially available magnesium hydrogen 1 To whom correspondence should be addressed. phosphate of formula MgHPO 4 r3H 2 O (Aldrich ref. 34,075-456