III International Conference

PP-II-157Supporting Pd on ZnO coated with polymers leads to significant improvement of thecatalysts’ properties. The Pd-PVPD complex showed higher activity and TON but lowerselectivity in hydrogenation of 3,7,11-trimethyldodecyne to 3,7,11-trimethyldodecene tocompare with Pd/ZnO and Pd-PEG/ZnO catalysts.Table 2. The results of cyclohexane (0.3 ml) oxidation with H 2 O 2 in acetonitrile (1.2 ml)on (Fe +M)/Al-Si catalysts (0.03 g), aluminosilicatesCatalystConversionof C 6 H 12 , %Cyclohexanol%Cyclohexanone%Ol/oneratio10%Fe-PHMG/Al-Si 22.3 15.7 6.6 2.410%(Fe+Cu)-PHMG/Al-Si 47.0 14.7 32.3 0.453%(Mn-Fe)-PHMG/ Al-Si 47.3 38.8 8.5 4.6Fe catalyst supported on aluminosilicate modified with polyhexamethyleneguanidine(PHMG) is less selective and active in oxidation of cyclohexane to compare with bimetalliccatalysts (Table 2). The yield of cyclohexanol is higher on the Cu-Fe catalyst. Cyclohexanonewith selectivity of 82 % is produced on the Mn-Fe catalysts. Cyclohexane conversion on theboth catalysts are about 47 %, TON is 400-600Figure 1. TEM image of the Pd-PEG/ZnO (a) and %(Mn-Fe)-PHMG/ Al-Si (b) catalystsabTEM study showed even distribution of the Pd nanoparticles with 2-3 nm sizes on thesurface of ZnO covered with PEG (Fig.1) Pd particles of different sizes are formed on ZnOwithout the polymer.Results of TEM study of the Cu-Fe and Mn-Fe catalysts on aluminosilicates (Al-Si)confirmed the decrease of metal particle sized on the surface of polymer-containing supports(Fig.1, b). IR-spectroscopy data confirm interaction of the polymers with metal ions andformation of complexes on the surface of supports.Thus, a simple method for preparation of active, selective and stable heterogeneouscatalysts with even distribution of metal nanoparticles on supports have been developed basedon strong adsorption of soluble polymer on carrier and binding of metal ions with functionalgroups of macromolecules. The procedure is carried out under mild conditions (ambienttemperature and atmospheric pressure, water as solvent).455