A DFT Study on Single Brønsted Acid Sites in Zeolite Beta and Their Interaction with Probe Molecules

Zeolites are subjects of intensive research, as they have vast industrial applications. However, exact nature catalytic active sites remains elusive. With this we attempt to shed light on the Brønsted acid in zeolite beta modification A and correlate widely used TPD methods their identification with theoretically determined strongest weakest sites. diverse set probe molecules a wide range strength conjugated acids is applied determine heats adsorption over protonated samples. The studied were acetonitrile, dimethyl sulfide, sulfoxide, isothiazole, pyridine, tetrahydrofuran, ammonia. It was found that heat correlated only partially. Only some strong able be identified, while site often identified correctly. To conclude, method zeolites studies delivers partially correct results, conclusions from such should treated caution.