Decamolybdodicobaltate (III) heteropolyanion: Structural, Spectroscopical, Thermal and Hydrotrating Catalytic Properties

C. CABELLO; F. CABRERIZO; A. ALVAREZ; H. THOMAS

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL

Año: 2002 vol. 186 p. 89 - 100

1381-1169

AbstractThe ammonium decamolybdodicobaltate(III) salt: (NH4)6[Co2Mo10O38H4]·7H2O (here in Co2Mo10) has been prepared and characterized. Then, their structural, spectroscopic and thermal properties have been investigated by some physical–chemical techniques as XRD, FT-IR, Raman, DRS, SEM–EDAX,TG, DTA, and temperature programmed reduction (TPR).According to these properties, some Co2Mo10/-Al2O3 catalysts have been prepared by equilibrium impregnation of the support with aqueous solution of ammonium salts. The Co2Mo10 isothermal adsorption on -Al2O3 at room temperature has been also investigated in the Mo range of 15–150molMo/ml. The hydrotreating (HDS of thiophene and HYD of cyclohexene) catalytic activity has been compared to both -Al2O3 supported Anderson phase [(NH4)3[CoMo6O24H6]·7H2O (here in CoMo6)] and Co–Mo conventional catalysts. The improving of activity for the Co2Mo10 and CoMo6 based catalysts is related to the heteropolyoxometalates adsorption process as to preparative conditions; whereas, the different activity between heteropoly-systems are undoubtedly related to the particular structure of the Co2Mo10 heteropolyanion. Keywords: Co–Mo/-Al2O3 hydrotreating catalysts; Heteropolyoxometalates; Ammonium; Decamolybdodicobaltate(III)