Title:	Atomistic Design of Hybrid Materials for Photoelectrochemical Conversion of Carbon Dioxide to Fuel
DNr:	SNIC 2014/1-284
Project Type:	SNIC Medium Compute
Principal Investigator:	Carlos Moyses Graca Araujo <moyses.araujo@kau.se>
Affiliation:	Uppsala universitet
Duration:	2014-10-01 – 2015-10-01
Classification:	10304 10407 10402
Homepage:	http://www.physics.uu.se/en/page/dr-c-moyses-araujo
Keywords:

Abstract

The purpose of this research proposal is to use first-principles calculations to design novel advanced materials for application in efficient solar-energy conversion into chemical fuels. The specific aims are: (i) To achieve fundamental understanding on the underlying mechanisms of the photoelectrocatalytic CO2 conversion to fuel, unveiling the atomic-level properties that govern the catalytic performance. (ii) To develop a new first-principles high-throughput screening system to search for suitable CO2 reduction photoelectrocatalysts. (iii) To contribute in the design of a novel photoelectrochemical catalyst made of abundant and environmentally friendly elements. We will use state of the art first-principles methods based on quantum and statistical mechanics, viz. density functional theory (DFT), molecular dynamics (MD) and Kinetic Monte Carlo simulations. MD simulations are well suited for simulating fast processes like diffusion in liquids. However, processes with higher energy barriers, like bond-breaking chemical reactions, can be treated in a much more efficient way by the use of Kinetic Monte Carlo [1, 2]. The electronic structure at finite temperature will be evaluated by using ab initio MD simulations. Here, a sequential MD/DTF scheme will be used where some snapshots of the simulation are chosen to carry out high-accurate single point DFT calculations, and then, the obtained electronic structures are averaged. The aim is to develop a methodology that allows for direct comparison with in-situ spectroscopy measurements. Such combined experiment-theory approach can be very efficient to unveil the underlying physics at atomic scale [3]. Besides that, the simulations will also be used to evaluate the free energy of different pathways of the chemical reactions. More specifically we are interested in the photoelectrochemical conversion of CO2 catalyzed by hybrid materials made of coordinate complexes adsorbed on oxide surfaces. The latter works as photosensitizer while the former is the electrocatalyst. In this project we will focus on Ru based complexes adsorbed on Ta2O5 following the successful experiment of Sato and co-workers [4]. By unveiling the underlying catalytic mechanisms in this system we will establish the basis for a novel first-principles high throughput screening system, which is the primary goal of our project. References: [1] L. Xu and G. Henkelman J. Chem. Phys. 129, 114104 (2008). [2] G. Henkelman, and H. Jónsson J. Chem. Phys. 115, 9657 (2001). [3] A. Hirata et al. Nature Mat. 10, 28 (2011). [4] S. Sato, T. Morikawa, S. Saeki, T. Kajino and T. Motohiro, Angew. Chem., Int. Ed. 49, 5101 (2010).