Calculation of microchannel parameters in aluminophosphate zeolites

• The real shape of the microchannels for a number of aluminophosphate zeolites is identified.
• Places for preferential localization of the sorbate molecules in the zeolite structure is determined.
• Theoretical values of the zeolite microchannel volumes is calculated.
• Calculated and experimental values of Henry constants for hydrogen adsorption at 77 K is compared.

Adsorption interaction of molecular hydrogen with framework atoms of aluminophosphate zeolites AlPO-5, -11, -8 and -36 were analyzed using a representative fragment of the structure with the volume about 32 nm3. Isopotential surfaces of the interaction between molecules were calculated. Isopotential surfaces with zero adsorption potential outline the shape of microchannels. Theoretical values of the zeolite microchannel volumes were calculated. Places for preferential localization of the sorbate molecules in the zeolite structure (places with the lowest adsorption potential) were determined for the Henry adsorption isotherm range. Calculated and experimental values of Henry constants for hydrogen adsorption at 77 K were compared.

Profile and the adsorption interaction potential of H2 - zeolite AlPO-36.Figure optionsDownload as PowerPoint slide