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Catalysts with no hazardous or toxic components are required for the selective hydrogenation of acetylenic bonds in the synthesis of pharmaceuticals, vitamins, nutraceuticals, and fragrances. The present work demonstrates that a high selectivity to alkene can be reached over a Pd-Fe-O/SiO 2 system prepared by the co-impregnation of a silica support with a solution of the metal precursors (NH 4 ) 3 [Fe(C 2 O 4 ) 3 ] and [Pd(NH 3 ) 4 ]Cl 2 followed by thermal treatment in hydrogen or in air at 400 °C. A DRIFT spectroscopic study of CO adsorption revealed large shifts in the position of the Pd n+ -CO bands for this system, indicating the strong effect of Fe n+ on the Pd electronic state, resulting in a decreased rate of double C=C bond hydrogenation and an increased selectivity of alkyne hydrogenation to alkene. The prepared catalysts consisted of mono- and bimetallic nanoparticles on an SiO 2 carrier and exhibited a selectivity as high as that of the commonly used Lindlar catalyst (which contains such hazardous components as lead and barium), while the activity of the Fe-Pd-O/SiO 2 catalyst was an order of magnitude higher. The hydrogenation of a triple bond over the proposed Pd-Fe catalyst opens the way to selective hydrogenation over nontoxic catalysts with a high yield and productivity. Taking into account a simple procedure of catalyst preparation, this direction provides a rationale for the large-scale implementation of these catalysts.

Because of the growing demand for high-quality fuels, the light cycle oil fraction improvement including cetane number improvement is important. The main way to reach this improvement is the ring opening of cyclic hydrocarbons, and a highly effective catalyst should be found. Cyclohexane ring openings are a possible option to investigate the catalyst activity. In this work, we investigated rhodium-loaded catalysts prepared using the commercially available industrial supports: single-component ones, SiO 2 and Al 2 O 3 ; and mixed oxides CaO + MgO + Al 2 O 3 and Na 2 O + SiO 2 + Al 2 O 3 . The catalysts were prepared by incipient wetness impregnation and investigated by N 2 low-temperature adsorption-desorption, XRD, XPS, DRS UV-Vis and DRIFT spectroscopy, SEM, and TEM with EDX. The catalytic tests were performed in cyclohexane ring opening in the range of 275-325 °C. The best result was demonstrated by the sample 1Rh/CaMgAlO: the selectivity to n -hexane was about 75% while the cyclohexane conversion was about 25% at 275 °C. The space-time yield was up to 12 mmol n -hexane g cat -1 h -1 .