Integrated theoretical and empirical studies for probing substrate-framework interactions in hierarchical catalysts

Abstract

Soft‐templating with siliceous surfactant is an established protocol for the synthesis of hierarchically‐porous aluminophosphates (HP AlPOs) with improved mass transport properties. Motivated by the enhanced performance of HP (Si)AlPOs in the Beckmann rearrangement of cyclohexanone oxime to the nylon‐6 precursor, ε‐caprolactam, we have undertaken an integrated theoretical and empirical study to investigate the catalytic potential of the siliceous mesopore network. Neutron scattering studies, in particular, have provided unique insight into substrate‐framework interactions in HP AlPOs, allowing reactive species to be studied, independent of the catalyst matrix. Reinforced by probe‐based FT‐IR, solid‐state NMR and computational modelling, neutron spectroscopy has revealed ambient‐temperature interactions between cyclohexanone oxime and the HP catalysts, vindicating substrate activation by silanol sites in the mesoporous network. These investigations highlight the power of integrative studies in achieving a molecular‐level understanding of catalyst mechanism, and demonstrate how synthetic methodology can be used maximize catalyst productivity.

More information

Identifiers

ORCID for Marina Carravetta: orcid.org/0000-0002-6296-2104

ORCID for Robert Raja: orcid.org/0000-0002-4161-7053

Catalogue record

Export record

Altmetrics