# Time‐of‐Flight Secondary Ion Mass Spectrometry Revealing the Organocatalyst Distribution in Functionalized Silica Monoliths

## TL;DR

This paper uses a specialized mass spectrometry technique to study how organocatalysts are distributed within functionalized silica monoliths, which is important for improving catalytic reactor performance.

## Contribution

The novel use of time-of-flight secondary ion mass spectrometry to visualize radial catalyst distribution in silica monoliths.

## Key findings

- Time-of-flight secondary ion mass spectrometry revealed the radial distribution of 4-dimethylaminopyridine in functionalized silica monoliths.
- The method provides insights not achievable through conventional techniques like physisorption or elemental analysis.
- This approach could improve the design and performance of heterogeneous flow catalysis reactors.

## Abstract

Hierarchically porous monolithic silica shows promise as a carrier material for immobilized organocatalysts. Conventional analysis usually includes physisorption, infrared spectroscopy and elemental analysis, among others, to elucidate the pore space and degree of functionalization of the material. However, these methods do not yield information about the spatial distribution of the organic species inside the monolithic reactor. In this work, time‐of‐flight secondary ion mass spectrometry has been applied to characterize the surface of organically functionalized silica monoliths. Cross sections of a silica monolith functionalized with 4‐dimethylaminopyridine were analyzed and the results were compared with physisorption and elemental analysis experiments of the same material. This way, insight into the radial distribution of the catalyst could be achieved, which might assist in interpreting the performance of such reactors in heterogeneous flow catalysis.

In this work, porous silica monoliths that have been functionalized for organocatalysis were investigated using time‐of‐flight secondary ion mass spectrometry to reveal the radial catalyst distribution inside the reactor which is usually not obtainable by conventional methods.