III International Conference

PP-II-131480Pt-concentration, mmol/l1210864Initial sampleSample afterhydrothermal synthesisat 150 o CPt content, %604020Non-desorbed species2Weak bounded apecies003 5 7 9 11 0 50 100 150 200eluent рНTreatment temperature, оСFig.1. Desorption data as a function of the eluent pH for 2% Pt/Al 2 O 3 samples.The ion exchange part of surface Pt-species considerably decreases by usinghydroxocomplexes surface synthesis method (hydrothermal synthesis). The part ofcoordinately bounded non-desorbed complexes increases up to 80 %. The change of thetemperature and the exposure time provides a desired ratio of different species. Thus, theapplication of the surface hydrolysis stage in the synthesis scheme leads to obtaining thedeeply hydrolyzed species onto the surface. They are able to react with oxide support bycoordination mechanism.х [PtCl 6 ] р-р + Al 2 O 3SorptionSurfacehydrolysisх (PtCl 3 O 3 ) пIon exchange complexesdesorptionх (PtCl 1,5 O 4.5 ) п0,3х (PtCl 1,9 O 4.1 ) пIon exchange complexesdesorption0,8х (PtCl 1,2 O 4.8 ) пFig. 2. Transformation scheme of chloride precursor of platinum in interaction withalumina and surface synthesis of hydroxocomplexses.32862).This work was supported by the Russian Foundation for Basic Research (grant 06-03-186