FTIR Distinction of Internal and External Bronsted Acidic Sites on Zeolite Particles

Distinctly different Bronsted acidic (BA) sites have been identified in certain zeolites using either diffuse reflectance or transmission FTIR spectroscopy.  Density functional theory indicates that this is due to different surface and bulk BA hydroxyls on these zeolite particles, which can have implications for their sorption and catalytic properties.