Potential energy surface and reactive collisions for the Au+H(2) system

Area of Science:

• Theoretical Chemistry
• Chemical Physics
• Computational Chemistry

Background:

• The reaction between gold atoms and hydrogen molecules is crucial for understanding gold-based catalysis.
• Accurate potential energy surfaces are essential for predicting reaction dynamics and mechanisms.

Purpose of the Study:

• To compute a global potential energy surface for the ground state of the Au((2)S)+H(2) reaction.
• To investigate the electronic states, conical intersections, and curve crossings relevant to the reaction.
• To elucidate the reaction mechanisms and dynamics using quantum and quasiclassical methods.

Main Methods:

• Ab initio calculations with relativistic pseudopotential for gold.
• Fitting a global potential energy surface.
• Quantum wave packet and quasiclassical trajectory calculations.
• Calculation of integral and differential cross sections.

Main Results:

• A global potential energy surface was obtained for the Au+H2 reaction.
• Several electronic states and their intersections were analyzed, revealing an insertion well.
• Dynamical calculations showed good agreement between quantum wave packet and quasiclassical trajectories.
• Two reaction mechanisms (direct and indirect insertion) were identified.

Conclusions:

• The study successfully characterized the potential energy surface and reaction dynamics for Au+H2.
• An insertion well, analogous to those in gold clusters, was identified and found to influence the reaction mechanism.
• The findings provide a detailed understanding of the direct and indirect pathways in this important chemical reaction.