Steam methane reforming ATR Autothermal reforming POX Partial oxidation LSF La1−xSrxF eO3−δ LSC La1−xSrxCoO3−δ PDF Powder Diffraction File PUS Powder Universal Spectrometer SSITKA Steady state isotopic transient kinetic analysis setup STP Standard temperature and pressure MS Mass Spectrometer MFC Mass flow controller XRD X-ray diffraction NPD Neutron powder diffraction TGA Thermogravimetric analysis XPS X-ray photoelectron spectroscopy vii LIST OF FIGURES viii

The reaction between CH 4 and framework oxygen of Pt promoted Ce x Zr 1-x O 2 (x = 0.25, 0.5, 0.75, 1) solid solutions was studied at 873 K for syngas (CO ? H 2 ) production. The homogeneity and cubic/tetragonal structure of the solid solutions were confirmed by powder X-ray diffraction. The thermodynamic properties of the solid solutions, connected with Ce 4? /Ce 3? redox reactions, were measured by titrating the oxygen content of the oxides after equilibration in flowing mixtures of H 2 and CO 2 with 10 -31 \ pO 2 \ 10 -22 atm. The transient reactions between the oxides and discrete pulses of CH 4 , as well as of isotopically labeled 13 CH 4 ? 12 CO mixtures (limited to the material with x = 0.25) were investigated and reactivity, conversion and selectivity were measured. A strong correlation between the thermodynamic properties of the oxides and the syngas selectivity was found. The 13 C scrambling in CO and CO 2 during co-feed experiments confirmed equilibration of these molecules with the oxides surfaces.

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