Terminal and Non Terminal Alkynes Partial Hydrogenation Catalyzed by Some d8 Transition Metal Complexes in Homogeneous and Heterogeneous Systems

LIPRANDI, DOMINGO; CAGNOLA, EDGARDO; LEDHEROS, CECILIA; BADANO, JUAN ; QUIROGA, MÓNICA

Hydrogenation

In Tech

Año: 2012;

[PdCl2(NH2(CH2)12CH3)2] and [RhCl(NH2(CH2)12CH3)3] were synthesized and tested as catalysts in homogeneous and heterogeneous condition for 1-heptyne or 3-hexyne partial hydrogenation using  g-Al2O3 or RX3 (a carbonaceous material) as support at mild operational conditions (P = 150 kPa and T up to 303K). The Lindar catalyst was used as a reference. Elemental Composition, XPS, IR and Absorption Spectroscopy results showed that the active catalytic species was the complex itself in each case. All of the catalytic systems exhibited a better performance than the Lindar catalyst. The analysis of activity and selectivity values allowed to say that the optimum system is the [RhCl(NH2(CH2)12CH3)3] either on g-Al2O3 or RX3, an heterogeneous catalyst with an electron-rich transition metal and a high content of an electron-donating ligand (NH2(CH2)12CH3) with a long chain hydrocarbon substituent. The complex catalytic behaviour could be explained by means of electronic and geometric effects.