Operando characterization of heterogeneously catalyzed gas- and multi-phase reactions using nuclear magnetic resonance imaging

Highlights

• Applications of nuclear magnetic resonance imaging (MRI) in chemical engineering.

• Overview of operando and in-situ studies of gas and multi-phase reactions.

• Challenges and possible future directions of operando MRI.

Abstract

Nuclear magnetic resonance imaging (MRI), a series of techniques exploiting the phenomenon of nuclear magnetic resonance (NMR), is a powerful toolkit for operando investigations of catalytic reactions. For instance, in a single experiment MRI can be used to generate two or three-dimensional images of species concentration, gas and liquid distribution, local temperatures, and gas or liquid flow. Performing such operando measurements of catalytic reactions allows to better understand how catalytic activity depends on the surface of the catalyst as well as on the surrounding reaction conditions. In combination with multi-scale models, this helps to understand and improve reaction processes.

In this perspective article, we discuss recent operando studies of gas and multi-phase reactions using MRI. We further list current challenges and discuss possible future directions of the field.