One Step Synthesis of Ball-Milled La0.6Ca0.4FeO3 Perovskite for CO2 Conversion via Reverse Water–Gas Shift Chemical Looping

This study investigates the synthesis of La0.6Ca0.4FeO3 (LCF) perovskite via a ball milling method for application in reverse water–gas shift chemical looping (RWGS-CL) for CO2-to-CO conversion. Unlike conventional wet-chemical routes such as the Pechini method, the ball milling approach offers a solvent-free, scalable synthesis using low-cost metal oxide precursors (e.g., La2O3, CaO, Fe2O3). Structural analysis by XRD confirmed the successful formation of single-phase cubic perovskite, with no secondary phases when using oxide precursors. Crystallite size increased with calcination temperature, from 118.9 Å (no calcination) to 404.3 Å (1050 °C). BET analysis revealed a decrease in surface area from 2.5 m2/g (no calcination) to 0.51 m2/g (1050 °C), consistent with sintering at higher temperatures. TPR-H2 and TPO-CO2 studies revealed that non-calcined LCF possesses slightly enhanced redox properties, with oxygen vacancy formation and CO2 reoxidation activity both at 500 °C. RWGS-CL experiments demonstrate that all LCF samples exhibit stable CO production (910–970 µmol/gLCF) over multiple cycles at 500 °C, with comparable performance across calcination conditions. A cost and sensitivity analysis reveals that the ball milling method had lower synthesis costs by approximately 92% at the laboratory-scale and 88% at the industrial-scale compared to the Pechini method, highlighting its strong potential for large-scale perovskite production.