(685b) Revisiting Ru As New Haber-Bosch Catalyst, Ru Nanoparticles Size and Shape Effect – Quantum Modelling

Ammonia synthesis process also called Haber-Bosch process is one of the largest energy consumers, 1-2 % of total energy supply is needed for ammonia production due to large pressures and temperatures needed for the synthesis. Fe was first catalyst used for Haber-Bosch process and is still used in industrial scale for ammonia production. Other transition metals are researched in order to obtain better reaction yields and selectivities or to produce ammonia under milder reaction conditions. Computational methods are gaining popularity for catalyst design, that is why we decided to provide detailed density functional theory (DFT) analysis of ammonia synthesis reaction over Ru nanoparticle catalyst with various shapes and sizes, which is one of the most promising catalyst for ammonia production.

First, we modelled Ru slab and used DFT calculations in order to construct energy profiles and determine adsorption energies, favourable adsorption sites and detailed reaction mechanism. We used GPAW, where wave function was described with plane waves (PW) with cut-off energy of 450 eV and k-points = 2x2x1. We applied dispersion correction DFT-D3 and dipole correction. Furthermore, NEB calculations with Climbing image were used to determine transition states. This was our base for further Ru nanoparticle investigation for ammonia synthesis. We modelled different sizes of Ru nanoparticles in shapes of cube, icosahedron, truncated icosahedron as well as octahedron, truncated octahedron and thin hexagon and showed the effect of size and shape of Ru nanoparticle on ammonia synthesis reaction, which, to our knowledge, has not been done before. Our work was focused on ideal Ru nanoparticle catalyst construction for ammonia synthesis reaction.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101022738.