Surface and textural properties of Zr-doped silica [xZrO(2)-(100 - x)SiO2] have been investigated as a function of zirconium content in the range of x = 5 to 50 (mol % Zr) via heating their respective xerogels (prepared with a novel sol-gel route developed recently) in air at 500 degreesC for 4 h. Nitrogen adsorption -desorption investigations (BET/BJH) on the 500 degreesC-heated samples show a maximum specific surface area of 484 m(2)g(-1) at x = 20, and a minimum of 105 m(2) g(-1) at x = 50. With increase of zirconium content, porosity of the Zr-doped silica can be tuned conveniently from the mesoporous (100 Angstrom) to the microporous (less than or equal to 20 Angstrom) region with unimodal (or nearly unimodal) pore size distributions. Material issues such as thermal reactions, oxide mixing level and formation mechanisms have also been investigated with FTIR. XRD, DTA/TGA, and XPS methods. It is found that silica networks have been significantly modified with the introduction of zirconium, and crystallization of ZrO2 in the doped silica occurs only at 903-953 degreesC. Moreover, surface analysis shows that there is no appreciable element enrichment in the surface region, whereas significant changes in binding energies of Zr 3d, Si 2p, and O 1s have been detected. The above observations are indications that a good mixing has been attained.