Cecilia R. Lederhos, Juan M. Badano, Monica E. Quiroga, Alfonso E. Ramirez, Jose J. Martinez and Hugo A. Rojas Pages 2782 - 2790 ( 9 )
Palladium and platinum nanoparticles on an activated carbon were used as catalysts in the citral hydrogenation reaction in liquid phase at 363 K and 620 kPa of hydrogen pressure. The effect of metallic precursor salt to prepare mono and bimetallic catalysts was evaluated using PdCl2, Pd(NO3)2 and H2PtCl6. X-ray Photoelectron Spectroscopy suggests that Pdº, Pdδ+ (with δ close to 0) and Ptº are present on the monometallic catalysts surface; while Pdδ+, Pdn+, Ptδ-and Ptδ+ (with δ ≅ 0 and n ≅ 2) are detected on the bimetallic Pd-Pt/C. Monometallic PtCl/C displayed a very low total conversion of citral. All Pd based catalysts (PdN/C, PdCl/C and Pd-Pt/C) were highly selective to citronellal and isopulegol (desired products). The bimetallic Pd-Pt/C was the most active and selective catalyst. Electrondeficient and electron-rich species, chlorine amount on carbon surface and the modification of surface groups produced during the catalysts synthesis played an important role on the selectivity values to obtained products.
Activated carbon, Citral, Hydrogenation, Nanoparticles, Palladium, Platinum.
Instituto de Investigaciones en Catalisis y Petroquimica (FIQ, UNL-CONICET), Santa Fe, Argentina.