A large fixed bed reactor for MRI operando experiments at elevated temperature and pressure

Recently, in situ studies using nuclear magnetic resonance (NMR) have shown the possibility to monitor local transport phenomena of gas-phase reactions inside opaque structures. Their application to heterogeneously catalyzed reactions remains challenging due to inherent temperature and pressure constraints. In this work, an NMR-compatible reactor was designed, manufactured, and tested, which can endure high temperatures and increased pressure. In temperature and pressure tests, the reactor withstood pressures up to 28 bars at room temperature and temperatures over 400 degrees C and exhibited only little magnetic shielding. Its applicability was demonstrated by performing the CO2 methanation reaction, which was measured operando for the first time by using a 3D magnetic resonance spectroscopic imaging sequence. The reactor design is described in detail, allowing its easy adaptation for different chemical reactions and other NMR measurements under challenging conditions.

Automated summary

A NMR-compatible reactor was designed, manufactured, and tested to monitor local transport phenomena and heterogeneously catalyzed reactions under challenging conditions. The reactor can withstand pressures up to 28 bars and temperatures over 400 degrees C, exhibiting little magnetic shielding during the tests. Its applicability is demonstrated by performing CO2 methanation reaction using a 3D magnetic resonance spectroscopic imaging sequence, allowing easy adaptation for different chemical reactions and other NMR measurements.