Amorphization effects on the basic sites of nanometric magnesium oxide.

Carreño, Neftalí Lenin Villarreal; Keyson, David; Escote, Marcia Tsuyama; Leite, Edson Roberto; Longo, Elson; Fajardo, Humberto Vieira; Probst, Luiz Fernando Dias; Valentini, Antoninho; Joya, Miryam Rincón; Pizani, Paulo Sergio

Amorphization effects on the basic sites of nanometric magnesium oxide.

Date

2008

Authors

Carreño, Neftalí Lenin Villarreal

Keyson, David

Escote, Marcia Tsuyama

Leite, Edson Roberto

Longo, Elson

Fajardo, Humberto Vieira

Probst, Luiz Fernando Dias

Valentini, Antoninho

Joya, Miryam Rincón

Pizani, Paulo Sergio

Abstract

The paper reports the catalytic action of the basic sites of nanocrystalline particles of rare earth-doped magnesium oxide in the aldolization reaction between acetone and methanol leading to the C–C bond formation of an a,b-unsaturated compound (methyl vinyl ketone), also forming methyl ethyl ketone and isopropyl alcohol. Undoped and doped MgO samples were prepared by high-energy mechanical milling of commercial Mg, Y and Ce oxide powders. Catalytic activity and surface basicity of these compounds were strongly influenced by doping and the time of mechanical milling (amorphization process). Such milling leads to the formation of nanocrystalline materials. Influence of mechanical processing of these compounds was investigated by means of N2 adsorption (BET), X-ray diffraction (XRD), TEM, CO2 chemisorption and room temperature photoluminescence emission. Strong changes of polar groups such as hydroxyl groups on the surface of the solid were directly related to the photoluminescence emission observed.

Keywords

Magnesium oxide, Amorphization, Photoluminescence, Catalysts

Citation

CARREÑO, N. L. V. et al. Amorphization effects on the basic sites of nanometric magnesium oxide. Croatica Chemica Acta, v. 81, p. 443-451, 2008. Disponível em: <http://hrcak.srce.hr/index.php?show=clanak&id_clanak_jezik=49337>. Acesso em: 20 abr. 2017.