Hydrogenation of benzene over ruthenium-exchanged montmorillonite in the presence of thiophene

Ruthenium-exchanged montmorillonite with different loading of ruthenium have been prepared and used for hydrogenation of benzene at 400–600 psi (27.6–41.4 bar) and 80 °C with or without the presence of thiophene. Preparation of the catalysts by ion-exchange process ensures a high dispersion of metal ions into the montmorillonite matrix. The catalytic reactions have been carried out in a PAAR autoclave reactor in the liquid phase. Under the experimental conditions of 500 psi (34.5 bar) hydrogen pressure and 100°C temperature, the benzene is completely hydrogenated. Further modifications of the catalysts with Cu(I) and Cu(II) ions have been attempted to improve the sulfur tolerance of the catalysts. Both, impregnation of Cu(II) salt on the montmorillonite and addition of CuI to the reaction mixture significantly improves the sulfur tolerance of the Ru ion-exchanged montmorillonite, thus, providing a new approach for developing sulfur-tolerating hydrogenation catalysts.