Amino acid-deep eutectic solvents/LaCoO3 mutualism system:Forming La-Co-C-O hybrid for low temperature methane catalytic oxidation

Abstract

Low-temperature high-efficiency catalysts are key for complete methane oxidation, whereas common perovskite catalysts still have much room to improve. Herein, a unique La-Co-C-O hybrid (phase composition of La2O2CO3/LaCoO3/Co3O4) was successfully synthesized via an amino acid-deep eutectic solvent/LaCoO3 mutualism system. The C-O bond connects each phase and decreases the bond energy of active Co-O, as well as a higher Co valence state and lattice oxygen content in the hybrid. The light-off temperature of the hybrid for complete methane oxidation is 366 °C, which is 112 °C lower than the light-off temperature of LaCoO3. The high conversion rate remains in the presence of water vapour or long-term reactions. Such excellent catalytic performance of the hybrid can be attributed to the broad path of methane adsorption and C–H cleavage on acid-basic sites. This work hence provides a facile process to tailor highly active catalysts for complete methane oxidation.