Micro-mesoporous MCM-41/ZSM-5 Supported Pt and Pd Catalysts for Hydroisomerization of C-8 Aromatic Fraction

Abstract The hierarchical MCM-41/ZSM-5 aluminosilicate synthesized via a double-template procedure using CTAB and TPAOH was applied as a support for Pt and Pd isomerization catalysts with metal loading of 0.5 wt.%. The formation of micro-ZSM-5, as well as meso-MCM-41 phases, was confirmed by XRD, TEM, SEM, and FT-IR. The element composition, textural properties and acidity both of MCM-41/ZSM-5 composite and noble metals supported catalysts were structurally characterized by TGA, N2 sorption, XRF, and NH3-TPD. Examining the catalytic evaluation of MCM-41/ZSM-5 supported Pt and Pd catalysts in hydroisomerization of C8 aromatic fraction in a fixed bed flow-type unit at 280-420 °C, LHSV of 1-6 h-1 and H2:feed of 1200-3600, showed that the Pt catalyst is more active compared to its industrial counterpart and provides high m-xylene and ethylbenzene conversions predominantly with p-xylene formation at 340 °C with LHSV of 1.0 h-1 (H2/feed = 2400) as well as for LHSV of 3.5 h-1 (H2/feed = 1200).