The Onset of Dehydrogenation in Solid Ammonia Borane: An Ab Initio Metadynamics Study

Area of Science:

• Materials Science
• Chemical Engineering
• Computational Chemistry

Background:

• Ammonia borane (AB) is a promising hydrogen storage material.
• Understanding AB dehydrogenation is crucial for its application.
• The solid-state reaction pathway remains unclear.

Purpose of the Study:

• To elucidate the atomistic details of ammonia borane dehydrogenation.
• To investigate the initial stages of hydrogen release from solid AB.
• To provide theoretical insights into complex solid-state reactions.

Main Methods:

• Ab-initio molecular dynamics simulations.
• Metadynamics simulations.
• Quantum-mechanical simulations on clusters.

Main Results:

• Formation of ammonia diborane initiates hydrogen release.
• Release of NH4+ triggers an autocatalytic H2 production cycle.
• Theoretical model for investigating complex solid-state reactions.

Conclusions:

• Ammonia borane dehydrogenation involves an autocatalytic cycle.
• Multiple ammonia borane molecules are necessary for the reaction.
• This work provides a framework for theoretical investigation of solid-state reactions.