Ni-containing CeO2 rods for dry reforming of methane: Activity tests and a multiscale lattice Boltzmann model analysis in two model geometries
Filip Strniša, Vikram Tatiparthi Sagar, Petar Djinović, Albin Pintar, Igor Plazl
Abstract
Experimental and theoretical modeling on low-temperature dry methane reforming over Ni-containing CeO 2 rods was studied. The catalyst was characterized by means of N 2 physisorption , in-situ XRD , TPR and H 2 chemisorption techniques. The characterization studies revealed the distortion of CeO 2 flourite structure due to the Ni incorporation. Lattice expansion (due to reduction) and contraction (due to oxidation) suggest the reversible redox nature of CeO 2 . Ni–O–Ce solid solution formation was evidenced by both XRD and TPR studies. H 2 chemisorption study revealed that the catalyst reduction temperature plays a significant role in Ni dispersion. The catalyst showed similar activity trends in two model geometries: a between-two-plates microchannel fixed-bed reactor and a conventional fixed-bed reactor. The activity tests were conducted in the kinetic regime, where conversions of CH 4 were not influenced with the gas flow rate . A lattice Boltzmann model for mixed gas flow was developed along with a boundary condition for catalytic sites. The lattice Boltzmann model was used in a multiscale simulation of the studied reaction systems and produced data that qualitatively matched the experiments.