Catalytic characteristics of metal catalysts and nitrate salt of a tripodal ligand in a basic medium for postcombustion CO₂ capture process

Amine-based postcombustion CO₂ capture technology has a great potential to control CO₂ emissions but is expensive because a huge amount of thermal energy is required for solvent regeneration due to poor CO₂ desorption kinetics. Tertiary amines can be efficiently regenerated, but the poor CO₂ absorption kinetics are a major limitation to its large-scale deployment. Here, we synthesized tripodal nitrate salt and its metal catalysts and investigated catalytic activity in a highly concentrated tertiary amine medium, N-methyldiethanolamine (MDEA), for the CO₂ capture process. To analyze the catalytic performance, the rate constant for CO₂ hydration, CO₂ absorption rate, and CO₂ desorption rate were experimentally studied. The gathered results suggest that catalyst 2 can improve the CO₂ absorption and CO₂ desorption efficiencies by 35% and 21%, respectively. On the basis of the obtained results, the possible reaction mechanism is also presented. These findings can provide a new route for energy-efficient CO₂ capture using tertiary amines.