Induced Active Sites by Adsorbate in Zeotype Materials

There has been a long debate on how and where active sites are created for molecular adsorption catalysis in zeolites, which underpin many important industrial applications. It is well accepted that Lewis acidic (LASs) basic (LBSs) as pristine zeolites generally believed to be the extra-framework Al species residue anion (OH–) formed at fixed crystallographic positions after their synthesis. However, dynamic interactions of adsorbates/reactants with zeotype materials “create” during real conditions remain largely unexplored. Herein, direct experimental observation establishment induced silicoaluminophosphate (SAPO) by an adsorbate first time made, contradicts traditional view materials. Evidence shows frustrated pair (FLP, three-coordinated framework LAS SiO (H) LBS) can transiently favored heterolytic binding/reactions competitive polar adsorbates due ineffective orbital overlap rigid framework. High-resolution magic-angle-spinning solid-state NMR, synchrotron X-ray diffraction, neutron powder situ diffuse reflectance infrared Fourier transform spectroscopy, ab initio dynamics demonstrate transformation typical Brønsted acid site (Al(OH)Si) SAPO new FLP structure hetereolytic binding upon strong adsorbate. Our unprecedented finding opens up avenue understanding or chemical reactions under bombardment zeolitic structures.