X-ray diffraction (XRD), selected area diffraction (SAD), radial distribution function (RDF) and high resolution transmission electron microscopy (HREM) techniques were used for studying the role of the Ru additives in the stabilization of carbon-supported palladium catalysts at high temperatures in hydrogen atmosphere of (250-650 degreesC) and under the action of reaction medium (250-285 degreesC) in process of terephthalic acid (TPA) hydropurification. It is shown that the introduction of ruthenium in the composition of palladium catalysts results in the increase of their sintering stability. A decrease in the dispersity of bimetallic catalysts at high temperatures happens mainly due to the sintering of Pd metal particles; the Ru particles in these conditions maintain a high dispersity and exist as an individual phase.