AUTHOR=Łodziana Zbigniew 

TITLE=Surface Properties of LaNi5 and TiFe—Future Opportunities of Theoretical Research in Hydrides

JOURNAL=Frontiers in Energy Research

VOLUME=Volume 9 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2021.719375

DOI=10.3389/fenrg.2021.719375

ISSN=2296-598X

ABSTRACT=Hydrogen in the solid state compounds is still considered as safe method of energy storage however,
the ultimate metal hydrides or other materials for this purpose remain unknown. Such metal hydride
shall have favorable thermodynamics and kinetics of hydrogen ad/desorption, it shall be resistant to
contamination of H2 and do not constitute any environmental hazards. Theoretical investigations
based on quantum mechanics approach have established position in modern materials research, however
their application for design new alloys for reversible hydrogen storage with tailored properties is
rarely present in the literature. The mainstream study deal with accurate prediction of thermodynamic
properties and crystal structures of hydrides with respect to composition or external parameters. On
the other hand, the effects related to kinetics of hydrogen transport or interaction between solid and
pure or contaminated hydrogen are more demanding. They cannot be easily automated. We present
the calculations of the equilibrium crystal shapes for LaNi5 and TiFe - two important materials that
show reversible hydrogen cycling near ambient conditions. The surface properties are crucial for
development of materials with better cyclability or resistant to hydrogen impurities. Indeed the adsorption
energy of carbon oxides or water is stronger than hydrogen, and these molecules block the
active sites for H2 dissociation. The present development of computational methods allows studies of
properties of intermetallics related to their surface or novel catalytic applications.