Ni-Ru-Containing Mixed Oxide-Based Composites As Precursors For Ethanol Steam Reforming Catalysts: Effect Of The Synthesis Methods On The Structural And Catalytic Properties

Ethanol steam reforming catalyst's precursors, i.e., nanocomposites of complex oxides with the general formula [Pr0.15Sm0.15Ce0.35Zr0.35O2 + LaMn0.45Ni0.45Ru0.1O3] (1:1 by mass), were synthesized by three different methods. It was shown that two synthesis methods - ultrasonic dispersion and sequential polymeric method, lead to the formation of the nanocomposite perovskite-fluorite system with the specific surface area up to 50 m(2)/g. Reduction of samples at 400-500 degrees C lead to the formation of Ni-Ru alloy nanoparticles strongly bound with the surface of oxide nanocomposite. Catalytic tests in ethanol steam reforming reaction at 500-600 degrees C showed the highest specific activity of the sample prepared by the sequential polymeric method due to the location of Ni- and Ru-containing perovskite mainly on the surface of the composite providing a high concentration of active metal centers. At higher temperatures for all samples, ethanol conversion approached 100% with hydrogen yield varying in the range of 65-75%. A study of spent catalysts confirmed the absence of carbon deposits after long-term catalytic tests at 650 degrees C.