Efficient CO2 conversion to CO using chemical looping over Co–In oxide

Abstract

CO₂ conversion to CO by reverse water-gas shift using chemical looping (RWGS-CL) can be conducted at lower temperatures (ca. 723–823 K) than the conventional catalytic RWGS (>973 K), and has been attracting attention as an efficient process for CO production from CO₂. In this study, Co–In₂O₃ was developed as an oxygen storage material (OSM) that can realize an efficient RWGS-CL process. Co–In₂O₃ showed a high CO₂ splitting rate in the mid-temperature range (723–823 K) compared with previously reported materials and had high durability through redox cycles. Importantly, the maximum CO₂ conversion in the CO₂ splitting step (ca. 80%) was much higher than the equilibrium conversion of catalytic RWGS in the mid-temperature range, indicating that Co–In₂O₃ is a suitable OSM for the RWGS-CL process.