Co-Ru/NaY catalyst:: Advanced catalytic system for selective CO hydrogenation

Co/NaY, Ru/NaY and Co-Ru/NaY samples have been prepared, characterized and studied in the CO hydrogenation. On one hand, synergism of ruthenium on cobalt in Co-Ru/NaY(I) sample was established, i.e. 0.4 wt % Ru on 4.1 wt % Co in NaY zeolite caused an increase in the rate and in the oxygenate selectivity in CO/H-2 reaction at 21 bar, while CO2 formation was fully suppressed. On the other hand, the effect of pretreatment on the rate and selectivity of Ru/NaY and Co-Ru/NaY(n) catalysts have been investigated. Direct oxidation of the ion exchanged Ru/NaY caused migration of RuO2 particles to external surface of NaY, thus, enhanced metal particle size and olefin formation, whereas no oxygenates were formed in the reaction performed at 1 bar pressure. Ruthenium nanoparticles were formed and stabilized either by He treatment or/and by added cobalt, and only a slight change was observed in the reaction parameters. The phenomenon is interpreted by the location and the size of the metal particles in NaY zeolite.