Enhancing CO2 uptake by aqueous K2CO3 solutions using H2O2-derived reactive oxygen species: Novel rate promotion for CCU processes

This study introduces a novel approach to promote CO2 absorption by aqueous K2CO3 solutions through the in-situ generation of reactive oxygen species (ROS) via the alkali activation of H2O2. The superoxide radical anion (O-2(center dot-)) is recognized as a major contributor in this process, with its presence confirmed by UV-Vis (Ultraviolet-visible) spectroscopy through the characteristic diformazan peak formed from the reaction between nitro blue tetrazolium (NBT) and superoxide. CO2 absorption experiments and C-13 NMR (Carbon-13 nuclear magnetic resonance) characterization demonstrate the enhanced efficiency of the promoted solution in both CO2 absorption and the conversion of K2CO3 to KHCO3. Comparative analysis with traditional promoters reveals the superior kinetic performance of the H2O2-promoted system at room temperature. Notably, our system yields pure KHCO3 without by-products, making it highly suitable for carbon capture and utilization (CCU) by enabling versatile subsequent transformation processes. (c) 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.