Search for dissertations about: "oxygen vacancy"

Showing result 1 - 5 of 29 swedish dissertations containing the words oxygen vacancy.

  1. 1. Oxygen Vacancy Chemistry in Ceria

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Jolla Kullgren; Uppsala universitet.; [2012]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ceria; Density Functional Theory; Oxygen storage; Nano crystals; Sulfur poisoning; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

    Abstract : Cerium(IV) oxide (CeO2), ceria, is an active metal oxide used in solid oxide fuel cells and for the purification of exhaust gases in vehicle emissions control. Behind these technically important applications of ceria lies one overriding feature, namely ceria's exceptional reduction-oxidation properties. READ MORE

  2. 2. Point defects and ion conduction in solid oxides: a first-principles case study of La2Zr2O7

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Joakim Nyman; [2010]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; proton; self compensation; hydrogen economy; DFT; La2Zr2O7; acceptor doping; lanthanum zirconate; oxygen vacancy; SOFC; pyrochlore; point defect; trapping; computational methods; solid oxide; charge compensation; first principles; ion conduction; solid oxide fuel cell; ceramic electrolyte; defect cluster; fuel cell; hydrogen;

    Abstract : In the endeavor to attain a clean environment and sustainable energy consumption, the notion of a future hydrogen economy stands out as one of the grandest visions. Striving for this vision, a critical task lies in optimizing the performance of the fuel-cell devices responsible for extracting electric power from the energy stored in hydrogen molecules. READ MORE

  3. 3. Mechanistic Approach to Corrosion of Zirconium by Water - A First Principle Study

    University dissertation from ; Chalmers tekniska högskola; Gothenburg

    Author : Mikaela Lindgren; [2018]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; zirconium; hydrogen pick-up; corrosion; oxygen vacancy; DFT;

    Abstract : Zirconium and zirconium oxides are of major technological importance. There are broad applications for these materials, from fuel cell electrolyte to semiconductors and in hip-implants. In nuclear power plants, zirconium alloys are widely used as cladding material to contain the fission fuel in the reactor cores. READ MORE

  4. 4. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

    University dissertation from ; Chalmers tekniska högskola; Gothenburg

    Author : Joakim Nyman; [2012]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

    Abstract : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. READ MORE

  5. 5. From the Electronic Structure of Point Defects to Functional Properties of Metals and Ceramics

    University dissertation from Stockholm : Materialvetenskap

    Author : David Andersson; KTH.; [2007]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; first principles; ab initio; density functional theory; Calphad; point defects; diffusion; solid electrolytes; oxygen storage materials; TECHNOLOGY Engineering physics Material physics with surface physics; TEKNIKVETENSKAP Teknisk fysik Materialfysik med ytfysik;

    Abstract : Point defects are an inherent part of crystalline materials and they influence important physical and chemical properties, such as diffusion, hardness, catalytic activity and phase stability. Increased understanding of point defects enables us to tailor the defect-related properties to the application at hand. READ MORE