Molecular Layer Deposition-Modified 5A Zeolite for Highly Efficient CO₂ Capture

Effective pore mouth size of 5A zeolite was engineered by depositing an ultrathin layer of microporous TiO 2 on its external surface and appropriate pore misalignment at the interface. As a result, a slightly bigger N 2 molecule (kinetic diameter: 0.364 nm) was effectively excluded, whereas CO 2 (kinetic diameter: 0.33 nm) adsorption was only influenced slightly. The prepared composite zeolite sorbents showed an ideal CO 2 /N 2 adsorption selectivity as high as ∼70, a 4-fold increase over uncoated zeolite sorbents, while maintaining a high CO 2 adsorption capacity (1.62 mmol/g at 0.5 bar and 25 °C) and a fast CO 2 adsorption rate.