Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-V-3DEVELOPMENT OF Pd/SIBUNIT CATALYSTS PREPARATIONTECHNIQUE FOR SYNTHESIS OF CHEMICALS FROMRENEWABLESO.A. Simakova 1, 2 , P.A. Simonov 2 , I.L. Simakova 2 , A.V. Romanenko 2 ,E.V. Murzina 1 , A.V. Tokarev 1 , D.Yu. Murzin 11 Åbo Akademi University, Turku/Åbo, Biskopsgatan, 8, 20500, Finland,Fax:+358 2 215 4479, e-mail: dmurzin@abo.fi2 Boreskov Institute of Catalysis, Pr. Ak. Lavrentieva, 5, Novosibirsk, 630090, Russia,Fax: +7 383 334 3056, e-mail: oasimak@catalysis.ruSupported palladium catalysts are widely used as catalysts for various industrial processesincluding several transformations of renewable resources. Although Pd catalysts preparationbased on PdII salt hydrolysis followed by deposition of palladium hydroxide at pH 5 - 6 on acarbon support was studied in the literature, complete information about catalysts obtained viapalladium hydroxide deposition at pH 8 – 10 is still unavailable. It is known that the higherpH of the catalyst precursor solution contacting with a support particle the more palladium islocated on its periphery [1]. In this work a set of 1% (wt) Pd/C and 4% (wt) Pd/C samples wasprepared by three deposition procedures at pH 8 – 10 (Methods I – III) and for comparison bydeposition at pH 5 – 6 (Method IV). Na/Pd molar ratio (χ) was varied from 5 to 21 inMethods I-IV. Samples were washed, dried at 373 K and reduced by hydrogen at 423 K.Catalytic activity and efficiency of the catalyst particles were tested in a model reaction,liquid-phase hydrogenation of cyclohexene at 273 K and PH2 =1 atm. Pd distributionthroughout the carbon grain was estimated by XPS measurements. The dispersion of Pdparticles was determined by the pulse CO-chemisorption technique at 298 K.1% (wt) Pd/C catalysts were applied in rapeseed oil hydrogenation. Products of thisreaction are used in fryingTable 1. Rapeseed oil hydrogenation over 1% (wt) Pd/C catalysts at 373 K.oils, margarines, etc.Method PdAccording to the literature(Na/Pd distribution DActivity, Trans/Cismolarthroughout (Pd),ml (H cis-trans isomerisation ofratio of the catalyst nm2 )/mg cat·sec ratio21) grainfatty acids occurs readilyI Uniform 2.0 3.8·10 –4 3.8 since both reactions,II Egg-shell 1.7 3.8·10 –4 1.7 doublebondIII Egg-shell 3.2 2.8·10 –4 2.9 hydrogenation andIV Egg-shell 1.9 6.4·10 –4 2.2 isomerisation, occur via462