Cumene hydroperoxide hydrogenation over Pd/C catalysts.

Pd/C catalysts were prepared by wet impregnation using K(2)PdCl(4) as precursor and their performance in hydrogenation of cumene hydroperoxide (CHP) was investigated. The catalytic activity was examined on the formaldehyde-reduced and on the hydrogen-reduced Pd/C catalysts. Results from XRD, TEM and CO chemisorption showed that reduction methods have a significant impact on the palladium particles size of resulting catalysts. Formaldehyde-reduced Pd/C catalyst has larger palladium particles than hydrogen-reduced Pd/C catalyst. Consequently, higher activity but lower selectivity to alpha-cumyl alcohol (CA) was obtained on formaldehyde-reduced Pd/C catalyst. Moreover, hydrogenation of CHP over hydrogen-reduced Pd/C catalyst can give similar CA selectivity to Na(2)SO(3) reduction process, an industrial process for CA production. High rate of CHP conversion and CA selectivity can be obtained at an elevated temperature and H(2) pressure. Kinetics studies revealed that CHP hydrogenation is zero-order for CHP concentration and the activation energy was calculated to be 13.6 kJ/mol. (c) 2009 Elsevier B.V. All rights reserved.