One Step Synthesis of Ball-Milled La_0.6Ca_0.4FeO₃ Perovskite for CO₂ Conversion via Reverse Water–Gas Shift Chemical Looping

This study investigates the synthesis of La_0.6Ca_0.4FeO₃ (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/g_LCF) 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.