Methane dry reforming with carbon dioxide was performed using perovskite-type mixed oxide catalysts, La1-xSrxNiO3 (x = 0, 0.1) and La2-xSrxNiO4 (x = 0-1) at 600-900°C and atmospheric pressure. Catalytic activity and resistance against coke formation were varied with the type of perovskite and the amount of Sr-substitution. LaNiO3 showed high activity without coke formation while La2NiO4 did not show any activity. Among Sr-substituted catalysts, La0.9Sr0.1NiO3 and La1.8Sr0.2NiO4 had the highest catalytic activity without coke formation. For these catalysts, initially the catalytic activity increased with time and then reached a steady state. The XRD spectra of used catalysts showed that catalysts were transformed to mixed phases of La2O2CO3 and SrCO3 with highly dispersed Ni metal during the reaction. This transformation could be caused by the removal of lattice oxygen by Sr-substitution, which was promoted by the reducing atmosphere of the reaction (CH4/CO2 = 1). The enhanced catalytic activity of Sr-substituted perovskite could come from dual active sites, La2O3 for CO2 adsorption and Ni for CH4 activation.
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry