About the project
The need of new renewable energy is increasing daily, due to the limited amount of petroleum in the world but mainly due to the environmental benefits of renewable and sustainable fuels. Among the energy vector most used, hydrogen is the most useful and most uses one. However hydrogen can be used as fuel for fuel cell, finding a cheap electrode for the fuel cell is still a challenge. One of the issues with cheaper compounds for electrode is the interaction with the hydrogen; this could lead to embrittlement, which is a major problem in material science, material physics and metallurgy. Four general mechanisms have been proposed: (i) formation of a hydride phase; (ii) enhanced local plasticity; (iii) grain boundary weakening and (iv) blister and bubble formation. The underlying atomic processes and relative importance of the four mechanisms remain uncertain.
One of the problems in the theories of hydrogen embrittlement is the lack of a comprehensive and coherent atomistic mechanism to account for the critical hydrogen concentrations at crack tips. Moreover, it is widely observed that hydrogen-enhanced dislocation mobility is the initial step to the embrittlement and that the fracture planes coincide with the slip plane of the material, which is not the typical situation; how all these phenomena come about still remains a mystery. Even more, the interactions of these compounds with hydrogen, when not in critical concentration, is still a answered question that will provided fundamental information and knowledge on how suitable the tested compounds are for fuel cell applications.
The main objectives of this project is to find the exact location of H as interstitial in metallic alloys, mainly Iron or titanium based alloys lattice and to describe the electronic structure and bonding. Even more, vacancies as hydrogen trap locations will be studied. First-principles ca1culations at the density functional level to examine the energetic and electronic structure for the relevant H-vacancy complexes in Fe and Fe-Metal alloys will be performed. Possibility of several Hydrogen simultaneously occupancy will be studied.
Our research program is focused on modeling the atomic features and molecular phenomena that govern surface science and metallurgy. We are using computational chemistry and modeling to examine the properties and performance for a range of metals, for use as H-resistant materials and potential electrodes for fuel cells. The performance of these materials depends on their atomic surface, bulk structure and composition. The chemistry and kinetics at a solid-gas interface are controlled by chemical bonding between the adsorbates and the surface as well as the environment at the active site. The final absorption of H on the metal alloy and the possibility to form vacancies is controlled by the changes in the metal-metal bond and the impurity defect interaction.
Publications from this project can be found in Cristin
Universidad Nacional del Sur