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

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