Toward a Comprehensive Understanding of Mode-Specific Dynamics of Polyatomic Reactions: A Full-Dimensional Quantum Dynamics Study of the H + NH₃ Reaction

Abstract

Mode specificity not only sheds light on reaction dynamics but also opens the door for chemical reaction control. This work reports a state-of-the-art full-dimensional quantum dynamics study on the prototypical hydrogen abstraction reaction of hydrogen with ammonia, which serves as a benchmark for advancing our fundamental understanding of polyatomic reaction dynamics. By taking advantage of the (3 + 1) Radau−Jacobi coordinates, the bond-specific probabilities are resolved with the reactant NH 3 initiated from either a nondegenerate or degenerate stretching vibrational state. The observed different atom-specific abstraction probabilities from individual states of the degenerate pair are rationalized in the local mode representation according to the different vibrational energy deposited in each N−H bond. It is verified that the three H atoms in NH 3 have the same abstraction probability as that from the degenerate pair and the linear combination of the degenerate pair gives the same reaction probability. In addition, the symmetric and asymmetric stretching modes of the reactant NH 3 have comparable efficacies on driving the reaction.

First-principles mode-specific reaction dynamics

“…show in the literature. 6,9,10,19,33,108,109 For larger systems the QCT approach provides an efficient tool to study mode-specific reactivity (see also Fig. 1), where the N-atomic non-linear (linear) reactants can be prepared in any vibrational state characterized by quantum numbers (n 1 , n 2 ,.…”

Hydrogen, Ammonia and Symbiotic/Smart Fertilizer Production Using Renewable Feedstock and CO2 Utilization through Catalytic Processes and Nonthermal Plasma with Novel Catalysts and In Situ Reactive Separation: A Roadmap for Sustainable and Innovation-Based Technology

“…Several theoretical papers based on modified DFT calculations have appeared and they are used in the interpretation of experimental results that are compatible with quantum effects in catalysis in photo-dissociation of CO 2 and H 2 O in particular [317][318][319][320][321][322] and polyatomic catalytic reactions in general [317,325,326].…”

Vibrational mode-specific quasi-classical trajectory studies for the two-channel HI + C2H5 reaction

“…27 The vibrational ground-state dynamics for the HI + C 2 H 5 reaction was also studied in that work. 21 Following previous mode-specific studies on various polyatomic reactions, 28–36 here we investigate the competition between vibrational and translational excitation in the nine-atomic two-channel HI + C 2 H 5 reaction, thereby providing new insights into the dynamics and mechanisms of the title reaction. The HI-stretching mode and three selected vibrational modes of ethyl are excited, one at a time and each with one quantum, at five different collision energies.…”