Pore structure of titania

Control of pore structures of titanias and titania/aluminas using complexing agents... 

Parameters of the porous structure of titania samples (pores volume Vs, specific surface area Ssp) were calculated using BET theory [34] from the adsorption isotherms of methanol. The average pore diameter (Dp) values were estimated from the differential curves of pore size distribution. 

An example is shown in Table 44 [613]. A typical Cr/silica-titania catalyst was impregnated to incipient wetness with concentrated, aqueous solutions of the nitrate salts of the alkaline earth metals. Then ammonium hydroxide was added to precipitate the alkaline metal hydroxide within and around the pore structure of the catalyst. After a few hours of aqueous alkaline aging, the catalyst was washed and dried. 

For most cases shown in Table 6, the sols after doping still remained stable. The pore structures of the coated samples after calcination do not differ that much from the corresponding uncoated samples, as shown in Table 6. However, mixing a salt containing an anion different from the anion of the acid used in pepetization could destabilize the sols. The pore structure of the samples derived from the unstable sols is very different from those derived from the stable sols. Similar results were observed for zirconia and titania sols [38, 39]. 

Gavrilov, V.Yu. and Zenkovets, G. A. (1996) Pore Structure of Zirconia and Zirconia-Titania Materials Prepared via Precipitation from Solution, Kinet. Katal., vol. 37, no. 4, pp. 617-621. 

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