Hydrocarbon Conversion Reactions over the Pt-Re Bimetallic Catalysts Modified by Sulfur

The reforming reaction is one of the most important catalytic processes in the petroleum industry. The object of this process is to increase the octane number of the naphtha fraction of the crude oil distillate by converting paraffins into aromatic compounds. The presence of Re in the Pt-Re bimetallic system significantly enhanced the stability and reactivity of the catalyst. The Pt-Re bimetallic catalyst shows its unique property of naphtha reforming when it is sulfided to suppress the high hydrogenolysis activity of Re. All experiments were performed in a stainless steel ultrahigh vacuum system equipped with an Auger electron spectrometer, low-energy electron diffraction optics, a quadrupole mass spectrometer, and an internal isolation cell for catalytic reactions. Initial sulfiding changed the selectivity of the catalysts. The most significant change was a decrease in hydrogenolysis activity and an increase in cyclization activity.