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 deterge nts. Pt, PtSn, PtGe and PtPb supported on gamma-Al2O3 doped with alkal ine metals were characterized and tested in the n-decane dehydrogenati on reaction. When alkaline metals are added to Pt/Al2O3 a promoting ef fect on the selectivity to olefins in the n-decane dehydrogenation is observed. Regarding PtSn/Al2O3-doped catalysts their performance depen ds on the alkaline metal used as dopant, the Sn content and the prepar ation method. Moreover these bimetallic catalysts show a better olefin yield and a lower selectivity to gases and aromatics than the monomet allic platinum catalysts. PtGe and PtPb based catalysts have an analog ous behavior to the PtSn one but its selectivity to olefins is lower.