Unbiased molecular dynamics for the direct determination of catalytic reaction times : paving the way beyond transition state theory

TL;DR

This paper introduces a novel computational framework combining the Hill relation and Adaptive Multilevel Splitting to accurately determine catalytic reaction rates beyond the limitations of traditional Transition State Theory, validated by two case studies.

Contribution

It presents an exact rate calculation method for complex catalytic systems that overcomes TST limitations, enabling more accurate kinetic studies.

Findings

Validated approach with water formation on gamma-alumina

Accurate rate constants for protonated isobutanol dehydration

Demonstrated importance of dynamical effects in catalysis

Abstract

This study address the computational determination of catalytic reaction rates by moving beyond traditional Transition State Theory (TST), addressing its limitations in complex systems. The Hill relation framework, integrated with Adaptive Multilevel Splitting (AMS), offers exact rate constants for stochastic dynamics, overcoming TST's assumptions and limitations such as recrossings and post-transition state bifurcations. Two case studies validate the approach: water formation on {\gamma}-alumina and protonated isobutanol dehydration in the gas phase, demonstrating consistency with DFT results and highlighting the importance of dynamical effects. This framework provides a robust, computationally feasible methodology for studying complex catalytic processes.