Hydrogenation/dehydrogenation of polycyclic aromatic hydrocarbons using ammonium tetrathiomolybdate as catalyst precursor

摘要

The hydrogenation and dehydrogenation behavior of naphthalene, phenanthrene, and pyrene using ammonium tetrathiomolybdate as a catalyst precursor were investigated via their product distribution and kinetic/thermodynamic parameters. Hydrogenation reactions were carried out in 25 ml microautoclave reactors at 350, 400, and 450℃ for various times up to equilibrium conditions. A lumped kinetic model was used to determine forward and reverse rate constants, which were then used to determine Arrhenius parameters. Enthalpy data were obtained and compared to values calculated in the literature. It was found that the temperature where dehydrogenation of hydroaromatics became favorable over hydrogenation reactions decreased with increasing ring size. This was also shown by an increasing thermodynamic control over the reactions as ring size increased.