A periodic density functional theory study of gallium-exchanged mordenite

Several reconstructions of catalytic active sites in gallium-exchanged mordenite have been analyzed using periodic density functional theory method. It is found that a number of structures in which gallium is present as Ga(III)Hx, Ga(II)Ga(II)Hx, and Ga(III)Ga(I)Hx can be reached under alkane dehydrogenation conditions. The transition barrier for the rate determining step in alkane dehydrogenation are evaluated. The values indicate that these gallium structures can catalyze alkane dehydrogenation and suggest an alternative reaction route in addition to those that have been proposed before.