Oferta para la realizacióon de Tesis Doctoral dentro del programa FPU2019 (Phd. offer within FPU2019 Program).
INTERMOL offers two possible projects ending in a Ph.D (Tesis Doctoral).
Publicada Convocatoria contratos predoctorales FPU 2019 (pinchar aquí/ click here)
“Almacenamiento de hidrógeno en materiales 2D nanoporosos dopados con iones”
The quest for clean, safe and affordable sources of energies has spurred research in many directions and one of the most promising combustible species that has been found is hydrogen since its combustion generates only water, releasing at the same time a great amount of energy. Hydrogen is the lightest molecule and the storage and release of this new generation of fuels is a key step in developing an attractive industrial manufactured product for a sustainable and green society[1].
Traditional storage devices including high pressure deposit, or liquid transport and storage are not suitable for individual or community uses and it might not be adequate even in large storage production and conversion facilities. To avoid these problems the use of porous materials has been presented as an efficient alternative because of the high specific surface that helps increasing the gravimetric capacity. We think that porous carbon materials are worth to explore as one of these candidates for hydrogen storage at a room temperature. Since the the binding of hydrogen molecules to these porous or nanoporous substrates is ruled by weak intermolecular forces, the management of transport and refilling operations will be simple and safe.
However, these interactions should be somehow stronger in order to increase the gravimetric capacity. Doping of carbon materials with alkali and alkali-earth metal has been proposed as a mean to enhance the adsorption energy while stabilizing the substrate against destruction during adsorption/desorption
process[2].
We propose to study the adsorption of hydrogen on ion-doped carbon materials as a reliable alternative for hydrogen storage. Our group has already experience in dealing with nanoporous materials [3-5], and is collaborating with other groups in the study of large clusters involving H2 with Li+, and Cs + [6].
The project includes the computation of adequate interaction potential energy surface, and classical and quantum Monte Carlo techniques for the adsorption problem. The dynamical processes and the proposition of nanoporous carbon materials will be dealt with molecular dynamics simulations with a special emphasis in the possible influence of quantum effects for what we will rely on quantum wave packet techniques and transition state theory[4].
References:
[1] J. Alonso et al., J. Material Res., 28, 499 (2013).
[2] A. Kaiser et al., Int. J. Hydrogen Energy, 43, 3078 (2017).
[3] M. Bartolomei et al., J. Phys. Chem. C, 118, 29966 (2014).
[4] A. Gijón et al., J. Phys. Chem. C., 121, 19751-19757 (2017).
[5] M. I. Hernández et al., J. Phys. Chem. A, 119, 10743 (2015).
[6] M. Rastogi et al., Phys. Chem. Chem. Phys., 20, 25569 (2018).
“2D membranes based on graphene and h-BN: permeation and diffusion of protons and hydrogen atoms”
In the last years two-dimensional (2D) materials have emerged as a new family of building blocks for membranes which are expected to achieve low transport resistance as well as high selectivity. Among them we highlight graphene and hexagonal boron nitride (h-BN) which have been recently reported (experiments from the group of Geim in Manchester (UK)) to allow proton or hydrogen conduction with low energy barriers, opening the possibility to use them as efficient proton transfer membranes or hydrogen isotope separation medium. However, how protons or hydrogens conduct across or along the 2D crystal is still unclear since recent theoretically predictions do not fully agree with the experimental findings.
The aim of this project is to theoretically provide a reliable interpretation of the above mentioned experimental results by means of density functional theory (DFT) and density functional tight binding (DFTB) approaches. In particular, the use of molecular prototypes to describe the membranes based on graphene and h-BN is first proposed and the possibility of their protonation/hydrogenation will be carefully investigated. Then, the different mechanisms capable to efficiently produce the proton /hydrogen permeation and diffusion across and along the 2D plane will be studied and assessed. The project will also take into account the role of the solvent, as well as that of the use of periodic models to describe the 2D membranes.