A Periodic Structure Density Functional Theory Study of Propylene Chemisorption in Acidic Chabazite:  Effect of Zeolite Structure Relaxation

Density functional theory (DFT) periodic structure calculations have been employed to investigate the interaction of propylene within the acidic chabazite zeolite (Si/Al = 11). In agreement with previous studies, it is found that secondary alkoxy formation is preferred over primary alkoxy formation. Steric constraints appear not to affect the course of the reaction. Analysis of the radial distribution of the zeolitic atoms with respect to the Brønsted site aluminum atom allows further insight into the reaction. Changes in the zeolite oxygen atom position are more significant than those of the zeolite silicon atoms. Relaxation of unit cell size and shape has a dramatic influence on energetic parameters of the reaction path.