第二届中国化学链会议

Chemical looping is a process-intensification tool that focuses on fossil fuel combustion, CO₂ capture, hydrocarbon valorization, energy storage, and various other important applications. Perovskite-structured LaFeO₃, a typical oxygen storage material, shows great potential for chemical looping partial oxidation and H₂O/CO₂ splitting. We report a simple and efficient strategy to enhance catalytic activity by tuning A-site cation defects in perovskite via a sol-gel method. Systematically, studies show that A-site cation defects affect the physical and chemical properties. With the A-site cation defect engineering, the crystallite size of the perovskite is reduced. The catalytic performance for methane oxidation and CO₂ splitting improves as the oxygen vacancy concentration increases. The A-site cation-deficient perovskite exhibits high activity and good catalytic performance, which makes it suitable for the partial oxidation of methane at 750 °C with high CO selectivity. In addition, the perovskite shows high stability in the successive CH₄ partial oxidation/CO₂ splitting redox cycles, with only a slight decrease in methane conversion and almost unchanged CO selectivity. The strategy of regulating A-site cation deletion is an effective method to regulate the oxygen vacancy concentration in perovskite metal oxides in chemical looping processes.
 

Perovskite, Defect, Chemical looping, Methane