VSE knjižnice (vzajemna bibliografsko-kataložna baza podatkov COBIB.SI)
  • Utilization of high specific surface area CuO-CeO2 catalysts for high temperature processes of hydrogen production : steam re-forming of ethanol and methane dry re-forming
    Djinović, Petar ...
    CuO-CeO2 mixed oxide catalysts with 10, 15, and 20 mol % CuO content were prepared by the hard template method using KIT-6 silica as a template. The applied synthesis method yields solids with BET ... surface area in excess of 147 m2/g, highly porous nanocrystalline CeO2 morphology and dispersion of CuO phase between 28 and 40%, corresponding to CuO particle size between 1.3 and 1.9 nm. Increasing the CuO content caused a decrease in dispersion of this phase and a further decrease of surface acid site abundance, determined by NH3chemisorption/TPD method, but improved the reducibility extent of CeO2 (14.5, 16.1 and 24.5% for CuCe10, CuCe15, and CuCe20 catalyst, respectively) and oxygen mobility of prepared powders. It was discovered during ethanol steam re-forming experiments that increasing CuO content is favorable in termsof ethanol conversion but also causes quicker catalyst deactivation, primarily as a result of sintering and loss of CuO dispersion. Reaction temperatures in excess of 550 °C strongly promoted ethanol dehydratation reaction, leading to a rise in methane production and extensive coking of the catalyst surface. Coking was slower in the case of CuO-CeO2 catalysts with a higher CuO content as a result of lower acid site abundance and more pronounced oxygen mobility. Temperatures in excess of 450 °C are required for any noticeable CO2 and CH4 conversion in methane dry re-forming reaction over CuO-CeO2 materials. The examined materials displayed steady performance duringstability tests at a reaction temperature of 650 °C, with catalysts containing 15 and 20 mol % CuO exhibiting the highest activity. Additionally, very low amounts of carbon were deposited on spent catalyst samples.
    Vrsta gradiva - članek, sestavni del
    Leto - 2010
    Jezik - angleški
    COBISS.SI-ID - 4378906