Plasma Chemical Looping: Unlocking High-Efficiency CO₂ Conversion to Clean CO at Mild Temperatures

Abstract

We propose a plasma chemical looping CO 2 splitting (PCLCS) approach that enables highly efficient CO 2 conversion into O 2 -free CO at mild temperatures. PCLCS achieves an impressive 84% CO 2 conversion and a 1.3 mmol g −1 CO yield, with no O 2 detected. Crucially, this strategy significantly lowers the temperature required for conventional chemical looping processes from 650 to 1000 °C to only 320 °C, demonstrating a robust synergy between plasma and the Ce 0.7 Zr 0.3 O 2 oxygen carrier (OC). Systematic experiments and density functional theory (DFT) calculations unveil the pivotal role of plasma in activating and partially decomposing CO 2 , yielding a mixture of CO, O 2 /O, and electronically/vibrationally excited CO 2 *. Notably, these excited CO 2 * species then efficiently decompose over the oxygen vacancies of the OCs, with a substantially reduced activation barrier (0.86 eV) compared to ground-state CO 2 (1.63 eV), contributing to the synergy. This work offers a promising and energy-efficient pathway for producing O 2 -free CO from inert CO 2 through the tailored interplay of plasma and OCs.