# Reaction Discovery in Porous Materials Using Periodic Nanoreactor Molecular Dynamics

## TL;DR

This paper introduces a new method to discover chemical reactions in porous materials, revealing both known and new pathways in a catalytic process.

## Contribution

The study presents a periodic ab initio nanoreactor molecular dynamics approach for autonomous reaction discovery in heterogeneous catalysis.

## Key findings

- A water-assisted tautomerization mechanism facilitates N2 formation in the SCR process.
- A novel radical-driven route to N2O was identified using the nanoreactor molecular dynamics method.
- Reactivity involving Brønsted acid sites of the zeolite framework was captured in simulations.

## Abstract

Understanding catalytic processes is essential for advancing energy‐efficient molecular transformations. In heterogeneous catalysis, porous materials such as zeolites play a central role due to their structural complexity and large surface area. Here, we present a periodic ab initio nanoreactor molecular dynamics (NMD) approach to investigate the reaction network of selective catalytic reduction (SCR) of NO over copper‐exchanged chabazite zeolites. This method enables autonomous discovery of both established and previously unreported pathways, including a water‐assisted tautomerization mechanism that facilitates N2 formation and a novel radical‐driven route to N2O. Notably, NMD simulations also capture reactivity involving Brønsted acid sites of the zeolite framework. By using automated reaction detection, a comprehensive reaction network was constructed, which elucidates the formation of both desired and undesired products. Refinement of the reaction path including free energy corrections by computing the phonon spectrum allows to make quantitative statements about the discovered reactions. The results of this work provide insight into the side‐reactions of SCR, and also demonstrate the versatility of NMD for agnostic reaction discovery of complex systems such as heterogeneous catalysis.

Autonomous reaction discovery using ab initio nanoreactor dynamics in combination with periodic density functional theory (DFT) computations elucidates the selective catalytic reduction of NO to N2 and side reactions forming N2O. This enables the autonomous discovery of reaction mechanisms including the Brønsted sites and proton shuttles, leading to a complex chemical reaction network. Free energy barriers of selected reaction pathways are provided.