CATALYSTS FOR THE SELECTIVE DEHYDROGENATION OF HIGH-MOLECULAR-WEIGHT PARAFFINS

Selective dehydrogenation of high molecular weight linear paraffins is an important process step for the production of biodegradable detergents. Pt, PtSn, PtGe and PtPb supported on gamma-Al2O3 doped with alkaline metals were characterized and tested in the n-decane dehydrogenation reaction. When alkaline metals are added to Pt/Al2O3 a promoting effect on the selectivity to olefins in the n-decane dehydrogenation is observed. Regarding PtSn/Al2O3-doped catalysts their performance depends on the alkaline metal used as dopant, the Sn content and the preparation method. Moreover these bimetallic catalysts show a better olefin yield and a lower selectivity to gases and aromatics than the monometallic platinum catalysts. PtGe and PtPb based catalysts have an analogous behavior to the PtSn one but its selectivity to olefins is lower.