Pt-Ru/SiO2 bimetallic catalysts were studied in the reaction of decalin ring opening. For comparison, a monometallic Ru/SiO2 catalyst was also tested. The main products of ring opening are isomeric alkylcyclohexanes C-9. Isomeric alkylcyclohexanes C-10 are formed to a lesser extent, while the linear paraffin C-10 is not observed. The lowest temperature of the process was found for the monometallic Ru-containing catalyst which affords an 80% decalin conversion already at 250 degrees C. The introduction of platinum significantly increases the value of the temperature affording the 50% decalin conversion, T-50. The method of preparation of bimetallic Pt- and Ru-containing catalysts (Pt after Ru (Pt@Ru), Ru after Pt (Ru@Pt) or simultaneous introduction (Pt + Ru)) affects the activity of the catalysts in the decalin ring opening reaction. The activity of bimetallic catalysts follows the order: Pt@Ru > Ru@Pt > Pt + Ru. The XRD and EXAFS studies and the results of catalytic experiments have shown that the bimetallic catalyst Pt@Ru in which the metals are in the form of segregated or isolated phases is maximally close in the properties to the monometallic catalyst.