These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: 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.
    Author: Djinović P, Batista J, Cehić B, Pintar A.
    Journal: J Phys Chem A; 2010 Mar 25; 114(11):3939-49. PubMed ID: 19883056.
    Abstract:
    CuO-CeO(2) 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 m(2)/g, highly porous nanocrystalline CeO(2) 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 NH(3) chemisorption/TPD method, but improved the reducibility extent of CeO(2) (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 terms of 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 degrees 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-CeO(2) catalysts with a higher CuO content as a result of lower acid site abundance and more pronounced oxygen mobility. Temperatures in excess of 450 degrees C are required for any noticeable CO(2) and CH(4) conversion in methane dry re-forming reaction over CuO-CeO(2) materials. The examined materials displayed steady performance during stability tests at a reaction temperature of 650 degrees 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.
    [Abstract] [Full Text] [Related] [New Search]