III International Conference

PP-II-157SOLUBLE POLYMERS IN DESIGN OF NANOSIZE HETEROGENEOUSCATALYSTSZharmagambetova A.D.V. Sokolsky Institute of Organic Catalysis and Electrochemisrty MS&HE RK,Almaty, Republic of KazakhstanE-mail:alima@nursat.kzA simple method for preparation of heterogeneous catalysts with even distribution ofmetal nanoparticles on supports have been developed. The procedure includes: a) polymeradsorption on a carrier; and b) fixation of transition metal ions on polymer coated oxides. Thedeveloped catalysts were studied with TEM and spectroscopic methods and tested insemihydrogenation of long-chain acetylene alcohols and cyclohexane oxidation with H 2 O 2under mild conditions.Active nanosized catalysts are formed by interaction of functionalised polymers withtransition metal salts [1,2]. However, the drawbacks of macromolecule supports are diffusionlimitation of the substrates to active centers often located inside polymer-metal globules andmechanical instability of such types of catalysts. These disadvantages can be overcome bysupporting polymer-metal complexes on inorganic carrier. The procedure includes:a) adsorption of polymer on sorbent; and b) fixation of transition metal ions on polymercoated surface of support [2-4]. The effect of the nature of supports as well as polymermodifierson activity, selectivity and stability of the prepared catalysts have been studied.Polyethylene glycol (PEG) as well as polyvinylpyrrolidone (PVPD) were found the bestmodifiers for preparation of nanosized Pd/oxide catalysts for semihydrogenation acetylenealcohols (Table 1). Bimetallic Fe-Cu and Fe-Mn on aluminosilicates (AL-Si) coated with N-containing polymers showed high activity and selectivity in cyclohexane oxidation withhydrogen peroxide under mild conditions (Table 2).Table 1. Hydrogenation of 3,7,11-trimethyldodcene-1-ol over supported palladiumcatalysts in ethanol at 40 o C and atmospheric pressure of hydrogenCatalyst (1% of Pd)W . 10 -4 , mole/l . sec TON S C=C ,%С≡ СС=СPd/ZnO 2,71 0,25 4400 91Pd-PEG/ZnO 6,23 0,01 3800 98Pd-PVPD/ZnO 27,97 0,04 62000 95454