Emilian Angelescu

Styrene hydrogenation on supported Pd, Fe and Pd-Fe/γ-Al2O3 catalysts

Abstract Bimetallic Pd-Fe/γ-Al2O3 catalysts with different concentration of palladium and 1 wt.% of iron were prepared via impregnation of Pd/γ-Al2O3 catalysts with Fe(NO3)3 solution and compared with corresponding monometallic Pd and Fe catalysts. The state of the supported components was studied by hydrogen chemisorption, ESR and Mossbauer spectroscopy; hydrogenation of styrene was also used as a test reaction. The hydrogenation was shown to proceed selectively to ethylbenzene on monometallic Pd catalysts and unselectively to the mixture of ethylbenzene and ethylcyclohexane on the Fe catalysts. Presence of 0.1 wt.% of palladium in the Pd Fe catalysts directed the hydrogenation exclusively to ethylbenzene while selectivity drops again upon increasing Pd loading to 0.3 and 0.5 wt.%. Possible reasons for such a non-trivial effect from the second metal are discussed.

Hydrotalcites (HTs) and mesoporous mixed oxides obtained from HTs, basic solid catalysts for cyclohexanone condensation

The effect of the insertion of REE (Y, Gd, Sm and La) in HTs structure to prepare mesoporous mixed oxides with different basic sites to be used as basic solid catalysts is studied. The mixed oxides derived from REE modified HT precursors proved to be active and selective catalysts in cyclohexanone condensation reaction. The catalytic behaviour is associated to basic properties and the presence of structural defects of the prepared catalysts.