Surfaces are where materials interact with the world, and their structure and properties control many processes and phenomena, including friction, adhesion, and corrosion. Surface chemical processes are also vital to technologies like catalysis and chemical sensing, where we want to control exactly how molecules bind to the surfaces and then react with other atoms and molecules. Research in this area focuses on characterizing the composition and structure of surfaces, thin films, and nanomaterials and relating this to material behavior in real-world applications.
Contact: Lindsay R. Merte
Atomic-scale structure
The properties of materials are ultimately determined by the arrangement of their constituent atoms, but for surfaces this can be very difficult to measure or predict. This is because the information we need concerns only the very outermost atoms of a solid. With most experimental techniques, this information is swamped by signals coming from the inside (the “bulk”) of the material. We use several specialized experimental techniques that give information about the surface and then use this information to figure out the structure, with help from theoretical modelling.
Publications:
Structure of an Ultrathin Oxide on Pt3Sn(111) Solved by Machine Learning Enhanced Global Optimization
L.R. Merte et al., Angew. Chem. Int. Ed. 2022, 61, e202204244. (link)
Structure of the SnO2(110)-(4×1) Surface
L.R. Merte et al., Phys. Rev. Lett. 2017, 119, 096102. (link)
Synchrotron X-ray methods
Most traditional methods for surface characterization require that the sample is kept in an extremely clean vacuum environment very different from what the material is exposed to in the “real” world. The powerful X-ray beams produced at synchrotron facilities—like the MAX IV Laboratory in Lund—enable us to study surfaces under realistic conditions: in gases or liquids, during heat treatment, during catalytic or electrochemical reactions, etc. We can also use synchrotron methods to get more detailed information about surfaces under vacuum conditions than we could with standard laboratory X-ray instruments. We use a variety of instruments at several synchrotron sources across Europe to study surface structure, composition, and processes.
Publications:
Oxidation of a Platinum-Tin Alloy Surface during Catalytic CO Oxidation
H.J. Wallander et al., J. Phys. Chem. C 2022, 126, 6258–6266. (link)
Oxidation and Reduction of Ir(100) Studied by High-Energy Surface X-ray Diffraction
S. Albertin et al., J. Phys. Chem. C 2022, 126, 5244–5255. (link)
Ultrathin and 2D oxides
Extremely thin sheets of material—less than 1 nanometer—behave very differently from thicker materials made of the same elements, and their novel properties can be exploited for a variety of applications. We want to understand how material interfaces and chemical environments influence the structure and properties of metal oxides that are only a few atomic layers thick, and how the structure and properties influence their performance in catalysis and other applications.
Publications:
Structural Changes in Monolayer Cobalt Oxides under Ambient Pressure CO and O2 Studied by In Situ Grazing-Incidence X-ray Absorption Fine Structure Spectroscopy
D. Gajdek et al., J. Phys. Chem. C 2022, 126, 3411–3418. (link)
Structure of two-dimensional Fe3O4
L. R. Merte et al., J. Chem. Phys. 2020, 152, 114705. (link)
Tuning the reactivity of ultra-thin oxides: NO adsorption on monolayer FeO(111)
L. R. Merte et al., Angew. Chem. Int. Ed. 2016, 55, 9267–9271. (link)