Promoting effect of iron on low-percentage alumina-rhenium and alumina-technetium catalysts for dehydrogenation of higher paraffins

The method of preparation of low-percentage bimetallic Re-Fe/Al2O3 and Tc-Fe/Al2O3 catalysts for C-H bond activation in higher alkanes (n-decane, n-dodecane) is proposed. Thermal reduction of ReFe/Al2O3 samples at 700 degrees C is shown to make their catalytic activity in n-dodecane conversion comparable with that of the analogous Pt-Fe/Al2O3 catalysts reduced by H-2 under the standard conditions (500 degrees C). A similar effect is observed upon promoting a technetium-containing catalyst. The selectivities in structure-insensitive dehydrogenation reactions of n-decane and n-dodecane on Re-Fe/Al2O3 and Tc-Fe/Al2O3 catalysts is by 10-18% higher than that on platinum-iron/alumina samples (84-92 and 74%, respectively).