Abertura seletiva de anéis sobre catalisadores Ir-Pt/Nb2O5 e Ir-Ru/Nb2O5

L.S. CARVALHO; C.L. PIECK; V.M. BENITEZ; M.C. RANGEL; S.P. LIMA; D.P. R. VÁSQUEZ

Montevideo

Congreso; XXV Congreso Iberoamericano de Catálisis; 2016

Federación Iberoamericana de Sociedades de Catálisis

In this work, activity and selectivity of Ir-Pt/Nb2O5 and Ir-Ru/Nb2O5 catalysts were evaluated in the selective ring opening reaction, using decalin as a proof molecule. Materials were prepared by impregnation of niobia with the metallic precursors solutions. The metals contents were chosen in order to obtain Ir/Pt or Ir/Ru atomic ratio equal to 2. The solids obtained were characterized by BET, TPR, TPD of ammonia and TEM, and its metallic function was evaluated by cyclohexane dehydrogenation and cyclopentane hydrogenolysis reactions. According to results, the hydrogenation activity of the metals grows in the order Ir<Rut<Pt, while the hydrogenolysis activity follows the order Ru<Pt<Ir. The addition of Pt or Ru to Ir increases its hydrogenolysis activity, effect more pronounced with Ir-Ru system, due the stronger interaction between these metals, with alloys formation. As a consequence of this and the presence of weak and moderated acidity sites, favorable to desirable reactions, 0,7%Ir-0,2%Ru/Nb2O5 showed the better performance during the decalin reaction, with higher selectivity to ring contraction and ring opening products and lower selectivity to dehydrogenation products, which are undesirable.