HEPT-1-YNE SEMI-HYDROGENATION REACTION OVER SUPPORTED Pd AND W CATALYST

C.R. LEDERHOS; M.J. MACCARRONE; J.M. BADANO; G. TORRES; F. COLOMA-PASCUAL; J.C. YORI; M.E. QUIROGA

APPLIED CATALYSIS A-GENERAL

ELSEVIER SCIENCE BV

Año: 2011 vol. 396 p. 170 - 176

0926-860X

In order to increase the production of olefins the semi-hydrogenation of alkynes has achieved industrial importance. In this sense catalysts with selective hydrogenation propertiesmay be of  potential interest. In this work mono and bimetallic Pd and W catalysts supported on ã-alumina with low metal content (2.4% W and 0.4% Pd) were prepared. XPS, XRD, TPR and hydrogen chemisorption techniques were used for the characterization. The effect of metallic precursor incorporation order and of the reduction temperature, on the activity and selectivity for the semi-hydrogenation of hept-1-yne at mild reaction conditions, were evaluated. Low-loaded palladium monometallic catalyst showed a high selectivity but it was the least active. Moreover, bimetallic catalysts proved to be more active than the classical Lindlar catalyst. The addition of Pd to the W/ -Al2O3 catalyst greatly improved the total conversion and the selectivity to the desired product. This was attributed to an electronic effect between f and d electrons of the metals. The bimetallic W-Pd catalyst treated in hydrogen at low temperature conditions (393 K) showed the highest activity and selectivity values