Hydrogen on PdAu surfaces: Diffusion and segregation

dc.contributor.authorEngedahl, Unni
dc.contributor.departmentChalmers tekniska högskola / Institutionen för fysik (Chalmers)sv
dc.contributor.departmentChalmers University of Technology / Department of Physics (Chalmers)en
dc.date.accessioned2019-07-03T14:16:31Z
dc.date.available2019-07-03T14:16:31Z
dc.date.issued2016
dc.description.abstractThe possibility for hydrogen to dissociate on palladium surfaces and to diffuse subsurface makes palladium interesting for hydrogen storage and membrane applications. The properties of palladium may be modified and tuned by metal alloying. It is clear that the mixing of the metals in the surface region depend on the gas phase and the operating conditions. In this thesis, Density Functional Theory (DFT) calculations have been used to investigate hydrogen adsorption on Pd3Au surfaces and by studying the fcc(111) surface composition as a function of coverage how hydrogen may change the alloy composition in the surface layer. In addition, the effect of alloying on hydrogen subsurface diffusion have been investigated. The surface layer is composed entirely of Au in the absence of hydrogen. Increasing the hydrogen coverage favors Pd segregation to the first and the second surface layer. The segregation is induced by the strong hydrogen-palladium bond. Alloying is found to have marked effects on the diffusion of hydrogen into the bulk of the metal. The most important changes with respect to the bare Pd metal is a reduction of the surface to subsurface barrier and a slightly higher barrier for diffusion in the interior of the alloy.
dc.identifier.urihttps://hdl.handle.net/20.500.12380/239152
dc.language.isoeng
dc.setspec.uppsokPhysicsChemistryMaths
dc.subjectLivsvetenskaper
dc.subjectGrundläggande vetenskaper
dc.subjectHållbar utveckling
dc.subjectInnovation och entreprenörskap (nyttiggörande)
dc.subjectFysik
dc.subjectLife Science
dc.subjectBasic Sciences
dc.subjectSustainable Development
dc.subjectInnovation & Entrepreneurship
dc.subjectPhysical Sciences
dc.titleHydrogen on PdAu surfaces: Diffusion and segregation
dc.type.degreeExamensarbete för masterexamensv
dc.type.degreeMaster Thesisen
dc.type.uppsokH
local.programmePhysics and astronomy (MPPAS), MSc
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