INFLUENCIA DE LA MADURACION HIDROTERMICA SOBRE LAS PROPIEDADES TEXTURALES Y CATALITICAS DE CATALIZADORES SULFATO-ZIRCONIA

M. BUSTO; M.A. D'AMATO; C.R. VERA; J.M. GRAU; C.L. PIECK; K. SHIMIZU

Villa Hermosa, Tabasco, México

Congreso; X Congreso Mexicano de Catálisis; 2008

Sociedad Mexicana de Catálisis

The alternative use of reflux aged zirconia gel as support in WO3 and SO42- doped catalysts for n-butane conversion was assessed.  Reflux aging greatly improved zirconia textural properties. The growth of the monoclinic phase was greatly suppressed and the initial area and sintering resistance were increased.  The specific surface area of reflux aged material with no sulfate or WO3 was almost 75 m2/g after calcination at 800 oC.  Oxoanion promotion of aged materials further increased the tetragonal/monoclinic ratio but the area increased only in the case of sulfated samples (220 m2/g after calcination at 600 oC).  For W promoted catalysts pore blocking by WO3 particles seemed to occur and their specific surface area decreased to 40-60 m2/g after calcining at 800 oC. Both promoted catalysts had very low activity in isomerization of n-butane. The effect of aging was explained in terms of a lattice refining process which eliminated surface crystalline defects which are needed for the creation of active sites.