Abstract: In situ solid-state nuclear magnetic resonance (NMR) offers a powerful means to study catalytic reactions under operating conditions. Standard solid-state NMR rotors typically struggle to match the pressure and temperature of active reactions during sampling. Here, we introduce specialized inserts for commercial solid-state NMR rotors capable of withstanding pressures from atmospheric to 618.3 kPa and temperatures ranging from room temperature up to 433 K. With this innovative design, we examine the isomerization of dihydroxyacetone (DHA) on Sn-MFI zeolite catalyst using in situ ¹H MAS NMR, revealing the presence of a gem-diols-type intermediate during the transformation of DHA into glyceraldehyde.

Key words: Solid-state NMR, in-situ technique, NMR rotors, catalytic reactions, spectroscopic characterization