III International Conference

PP-III-594 hours in an air atmosphere. Under the chosen treatment conditions all processes werecompletely finished, i.e. weight of the samples stayed constant with increasing temperatureand time of treatment. After calcination samples looked like white fibres. Scanning ElectronMicroscopy (SEM) data show that obtained zirconium oxide reproduces the structure ofsawdust. The less amount of zirconia is contained in the initial sample – the more porous andbulk is the structure of the final oxide. Data on the surface area of obtained zirconiadepending on the composition of the initial mixture are presented in Table 1.Table1ZrO 2 /sawdust, w/w BET SA, m 2 /g1/1 131/10 38Thus, decreasing the amount of zirconia in initial samples leads to obtaining largersurface area of ZrO 2 . To find out if two-stage process (pyrolysis and calcinations) isimportant, ZrO 2 was prepared by calcination of precursor (ZrO 2 /sawdust=1/10, 600 o С4 hours) avoiding carbonization stage. The surface area of this oxide appeared to be a few lessthan that of the one of the same ratio (1/10) obtained in the two-stage process and amountedto 33 m 2 /g. It can be explained in the following way: during carbonization ZrO 2 is fixed onthe surface of carbon and thus carbon support prevents from oxide agglomeration. The fiberstructure of zirconia and possible presence of mineral matter in the sawdust [3], thatcontribute to the composition of final ZrO 2 , can influence its calalytic properties.References1. K. Tanabe. Catalysts and catalytical processes. Moscow. Mir. 1993. P.128-134.2. A.Muto, T.Bhaskar, Y.Kaneshiro, Md.A.Uddin, Y.Sakata, Y.Kusano, K.Murakami // GreenChem. 2003. V.5. P.480-483.3. K.Raveendran, A.Ganesh, K.Khilart // Fuel. 1995. V.74. №12. P.1812-1822.582