Transition metal oxides have been studied extensively over the last few decades, due to their electro optical and catalytic properties.The overall properties of these oxides and the heterostructures that can be built on them depend upon the surface structure, composition and morphology. However, the available information on the surface structures of transition metal oxides is scarce and often contradictory. Knowledge of the atomic structure of the catalytically active surfaces and of the adsorbed reactants and intermediates under in-situ reaction conditions is crucial for an understanding of catalytic oxidation at the molecular level, and will subsequently create possibilities for faster development of new catalysts, improve their performance on industrial level, and lower the costs associated with processing. The objective of the current work is to develop and apply the available experimental (UHV chambers, UHV-HREM, catalytic treatment chamber) and computational techniques (Direct Methods analysis and multislice simulations of electron diffraction data) to improve understanding of catalytic phenomena under various environmental conditions.