Speaker
Description
Introduction
Artificial ammonia production is mainly based on the Haber-Bosch process, which requires a high energy input to activate the inert and stable nitrogen molecule. Photocatalysis is an alternative for environmentally friendly ammonia production using light, nitrogen and water [1]. Theoretical methods at the atomistic level can provide significant insight into the structure and properties of the photocatalyst, which is useful for intelligent design aimed at improving yields [2].
Methods
Density functional theory (DFT) and time-dependent density functional theory (TDDFT) are used to study the properties of titanium dioxide (TiO$_2$) and ruthenium-titanium dioxide (Ru/TiO$_2$) clusters ((TiO$_2$)$_n$, n=1-12). The calculations are performed in GPAW [3] using the PAW method and the plane-wave basis set. The PBE functional is used for geometry optimization, while hybrid functionals are used to study the electronic properties and TDDFT for the dynamic properties.
Results
First, the clusters are optimized and the electronic properties calculated. Ruthenium atoms are added to the clusters to improve their properties for ammonia production. Lastly, the adsorption modes of the nitrogen molecule, hydrogen atom and ammonia molecule on both cluster types (pristine and Ru-doped) and the corresponding change of properties are calculated.
Conclusion
Knowing structural and electronic properties of TiO$_2$ clusters are essential for further understanding and investigation of the nitrogen photoreduction mechanism.
References
[1] Ithisuphalap, K. et al. Photocatalysis and Photoelectrocatalysis Methods of Nitrogen Reduction for Sustainable Ammonia Synthesis. Small Methods 3, 1–20 (2019).
[2] Meng, X., Yun, N. & Zhang, Z. Recent advances in computational photocatalysis: A review. Can. J. Chem. Eng. 97, 1982–1998 (2019).
[3] Mortensen, J. J., Hansen, L. B. & Jacobsen, K. W. Real-space grid implementation of the projector augmented wave method. Phys. Rev. B - Condens. Matter Mater. Phys. 71, 1–11 (2005).
| Speaker Country | Slovenia |
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