Mesoporous MgO enriched in Lewis base sites as effective catalysts for efficient CO₂ capture

Capturing CO₂ has become increasingly important. However, wide industrial applications of conventional CO₂ capture technologies are limited by their slow CO₂ sorption and desorption kinetics. Accordingly, this research is designed to overcome the challenge by synthesizing mesoporous MgO nanoparticles (MgO-NPs) with a new method that uses PEG 1500 as a soft template. MgO surface structure is nonstoichiometric due to its distinctive shape; the abundant Lewis base sites provided by oxygen vacancies promote CO₂ capture. Adding 2 wt % MgO-NPs to 20 wt % monoethanolamine (MEA) can increase the breakthrough time (the time with 90% CO₂ capturing efficiency) by ∼3000% and can increase the CO₂ absorption capacity within the breakthrough time by ∼3660%. The data suggest that MgO-NPs can accelerate the rate and increase CO₂ desorption capacity by up to ∼8740% and ∼2290% at 90 °C, respectively. Also, the excellent stability of the system within 50 cycles is verified. These findings demonstrate a new strategy to innovate MEA absorbents currently widely used in commercial post-combustion CO₂ capture plants.