The Conversion of Butadiene on Thiophene Hydrodesulfurization Catalysts

The production of thiophene via heterocyclization of butadiene with sulfur (hcycl.) has been studied in the interaction of butadiene with sulfided, alumina supported nickel (Ni6), molybdena–alumina (Mo6) and nickel promoted molybdena–alumina of a 0.35 atomic ratio of Ni:Mo (NiMo0.35). The sequence of the rates of thiophene production on these catalysts in a circulation system was the same (hcyclmNiMo0.35 > hcyclmMo6 > hcyclmNi6) than that for thiophene hydrodesulfurization observed before. The virtual activation energy values of the butadiene heterocyclization have been determined and compared with those of thiophene hydrodesulfurization determined before and with the strengths of bonds between reacting atoms and the different catalysts indicate calculated before. This comparison indicates that desorption of the product is the rate determining step in the butadiene heterocyclization.