Widger et al. (https://doi.org/10.1016/j.ijggc.2019.04.002) synthesised zinc(II) complexes [ZnII(PSAAMP)Cl2] (1) and [ZnII(PSAMEA)Cl2] (2) to enhance CO2 absorption using amine solvent. They reported that the mass transfer was enhanced by 20-55% from lab-experiments with the addition of the developed Zn additives. Their DFT calculations indicated that the complex of this Zn additive catalysed CO2 hydration.
The authors also investigated the stability of the solvent with the addition of Zn-additive. As shown in their Figure 6 and section 3.3 discussion, the material was stable at 145 °C for up to 96 h, even when 1000 ppm NOx and SOx were added. The authors also proposed the catalytic cycle of CO2 hydration using the developed additive.