ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Effect of support on activity of palladium catalysts in nitrobenzene hydrogenation

Ľubomír Pikna, Mária Heželová, Silvia Demčáková, Miroslava Smrčová, Beatrice Plešingerová, Michal Štefanko, Mária Turáková, Milan Králik, Pavel Puliš, and Peter Lehocký

Faculty of Metallurgy, Technical University of Košice, Letná 9, 042 00, Košice, Slovakia

E-mail: lubomir.pikna@tuke.sk

Abstract: The effect of two types of catalysts on the activity of the catalytic hydrogenation of nitrobenzene was studied. Catalysts were prepared by the surface deposition of palladium hydroxide with a simultaneous reduction with formaldehyde in a basic environment and were characterised by X-ray powder diffraction, transmission electron microscopy, adsorption-desorption, and catalytic tests — hydrogenation of nitrobenzene in methanol. The influence of the supports’ (activated carbon and a mixture of activated carbon and multi-walled carbon nanotubes) surface area is discussed. Despite having a size comparable (4–5 nm) to crystallites of metallic palladium, the catalyst prepared on a mixture of activated carbon and nanotubes (Pd/C/CNT) was significantly less active than the catalyst prepared on pure activated carbon (Pd/C); the rate of this reaction was approximately 30 % lower than the initial reaction rate. This feature could be attributed to the lower specific surface area of the Pd/C/CNT (531 m² g⁻¹) in comparison with the Pd/C (692 m² g⁻¹).

Keywords: palladium catalyst – activated carbon – nanotubes – hydrogenation – nitrobenzene

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0497-3

Chemical Papers 68 (5) 591–598 (2014)