Repulsive Lateral Interaction of Water Molecules at the Initial Stages of Adsorption in Microporous AlPO4-11 According to 27Al NMR and DFT

Ilya V Yakovlev; Aleksandr A Shubin; Evgeniy S Papulovskiy; Alexander V Toktarev; Olga B Lapina

doi:10.1021/acs.langmuir.3c03969

Repulsive Lateral Interaction of Water Molecules at the Initial Stages of Adsorption in Microporous AlPO₄-11 According to ²⁷Al NMR and DFT

Langmuir. 2024 Mar 26;40(12):6384-6393. doi: 10.1021/acs.langmuir.3c03969. Epub 2024 Mar 12.

Authors

Ilya V Yakovlev^{1

2}, Aleksandr A Shubin³, Evgeniy S Papulovskiy¹, Alexander V Toktarev¹, Olga B Lapina^{1

2}

Affiliations

¹ Boreskov Institute of Catalysis, Prospekt Lavrentieva 5, 630090 Novosibirsk, Russia.
² Novosibirsk State University, ul. Pirogova 1, 630090 Novosibirsk, Russia.
³ Institute of Solid State Chemistry and Mechanochemistry, Kutateladze 18, 630090 Novosibirsk, Russia.

PMID: 38475698
DOI: 10.1021/acs.langmuir.3c03969

Abstract

Lateral (adsorbate-adsorbate) interactions between adsorbed molecules affect various physical and chemical properties of microporous adsorbents and catalysts, influencing their functional properties. In this work, we studied the hydration of microporous AlPO₄-11 aluminophosphate, which has an unusually ordered structure upon adsorption of water vapor, and according to ²⁷Al NMR data, only tetrahedrally or octahedrally coordinated Al sites are present in the AlPO₄-11. These ²⁷Al NMR data are consistent with the results of density functional theory (DFT) calculations of hydrated AlPO₄-11, which revealed the presence of a strong repulsive lateral interaction at the initial stage of adsorption, suppressing the adsorption of water on neighboring (separated by one -O-P-O- bridge) Al crystallographic sites. As a result, of all the different aluminum sites, only half of the Al1 sites adsorb two water molecules and acquire octahedral coordination.