Oxygen Storage Characteristics and Redox Behaviors of Lanthanum Perovskite Oxides with Transition Metals in the B-Sites

Perovskites are typical oxygen storage materials that find many chemical, energy, and environmental applications. Lanthanum-based perovskite oxides represent a large family of oxygen carriers for chemical looping processes. Oxygen storage and redox behaviors are crucial for efficient activation of C–H/C═O, selective oxidation/combustion, heat management for chemical looping, or lattice oxygen-related reactions. The present work studied oxygen releasing/acquiring behaviors of lanthanum-based perovskite oxides with different B-site transition metals (Fe, Co, Ni, Cr, Mn, Al, Cu, and V) in CH4/CO/H2 and CO2/O2 by means of thermodynamic analysis, temperature programmed reduction/oxidation (TPR/TPO) experiments, and kinetics study. The oxygen release capacities obtained from H2-TPR followed an order of LaCoO3 > LaNiO3 > La2CuO4 > LaVO4 > LaMnO3 > LaFeO3 ≫ LaAlO3 ≈ LaCrO3, and all hydrogen-reduced perovskite oxides showed good regeneration ability in O2-TPO except LaNiO3 due to the sintering of metallic Ni. Except inner properties of Al and Cr perovskite oxides, lanthanum-based perovskite oxides (Co, Ni, Cu, V, Mn, and Fe) were able to donate lattice oxygen for fuel oxidation, and the reducibility follows an order of H2 > CO > CH4. In addition to O2, CO2 could fully or partially regenerate lattice oxygen for most H2-reduced perovskite oxides at higher temperatures above 700 °C and the H2-reduced LaFeO3 could be oxidized with CO2 starting at 500 °C. La2CuO4, LaMnO3, LaCoO3, and LaNiO3 might be suitable candidates for chemical looping air separation/combustion/selective hydrogen combustion at low temperatures (250–550 °C). LaFeO3 is suitable for chemical looping partial oxidation of CH4/CO2 splitting but with high reduction temperatures. This work provides a valuable reference for developing suitable oxygen carriers or redox catalysts for chemical looping or related processes.