Morphology of the CeO2/ZrO2 support was found to be significantly influenced by its synthesis method. XRD characterization revealed different extents of ceria-zirconia solid solution formation with Zr4+ ions substituting Ce4+ ions in the FCC lattice of CeO2. Oxygen mobility within the distorted CeO2 crystalline lattice was found to be strongly connected to the average CeO2 crystallite size and the degree of Zr4+ substitution. Along with the selection of proper operating conditions to minimize thermodynamic driving force for coke formation, these are crucial for enabling stable and carbon-accumulation-free methane dry reforming of undiluted equimolar streams of methane and carbon dioxide on time scale longer than 150 h.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 5254682Results obtained over the 3NiCo/CeO2-ZrO2 catalyst revealed that this solid can be very effectively used for catalytic transformation of simulated moist biogas streams with surplus methane into hydrogen-rich syngas. The examined catalyst exhibits only moderate deactivation during the 150 h time on stream. When feed gas composition is oxidant rich, i.e. n(H2O+CO2)/n(CH4) ≥ 1, coke accumulation on the catalyst surface can be completely avoided.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 5325338Different methods for synthesis of CeZr supports were ranked upon their effectiveness in producing CeZr solid solution, which facilitates thermal stability and oxygen mobility. Different loadings of nickel and cobalt were deposited over these supports and tested in methane dry reforming reaction, where high NiCo dispersion and oxygen storage capacity of the CeZr support were discovered as crucial for enabling successful prevention of coke buildup. An optimized NiCo/Ce0.8Zr0.2O2 catalyst was able to perform selective reforming (78 and 83 % conversion of CH4 and CO2, H2/CO = 0.85) of equimolar CH4/CO2 stream with no coke accumulation for more than 400 h.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 5316378