Immobilized Pd complexes over MCM-41 as supported catalysts for effective reformation of hydrocarbons

Abstract

The ethylthio alkane ligands i.e. di(ethylthio)ethane, I, and di(ethylthio)propane, II, have been used for the synthesis of Pd(II) complexes. These complexes were covalently anchored to the modified MCM-41 matrix as supported hybrid catalysts (MCM-41/I as Pd–I and MCM-41/II as Pd–II). Remarkable catalytic effects were observed when these supported catalysts act in n-hexane and n-heptane reformation reactions in the presence of H₂. Catalyst Pd–I provided the high TONs of 2325 with 91% selectivity for n-hexane and high TONs of 2145 with 88% selectivity for n-heptane under optimized and relatively mild conditions. A carbenium-based mechanism has been included to explain the product formation. TGA analysis indicates that these catalysts were thermally stable up to the reaction temperature and recyclable for further utilization.