One of the fundamental fields of research is oxidation catalysis by transition metal atoms and ions (TMA, TMI), located at gas/solid oxide or liquid/solid oxide interfaces, because of its importance in chemistry, biochemistry and modern technology. When TM oxide is dispersed on a second oxide phase playing the role of a support, a number of phenomena may take place, as revealed by UPS, XPS, AES, STM, IR and Raman spectroscopies. The TM oxide may be dispersed on the surface in form of isolated TM-oxygen polyhedra, their clusters, a monolayer or small crystallites, the TMI may diffuse into subsurface layer to form solid solution, or may form surface bidimensional compounds. The type of the process will depend on chemical properties of both oxides, their surface free energies, type and structure of the support, method and temperature of preparation. The resulting surface electronic structure determines the conditions of the exchange of electrons between the reacting molecules of the catalytic reaction and the catalyst and hence the catalytic activity. The surface of a catalyst for selective oxidation must be tailored to perform complex multistep operations on reacting molecules, hindering interactions leading to unwanted byproducts. Active sites must be generated which could accelerate following elementary steps: - activate the hydrocarbon molecule, which should be adsorbed in a proper way, by abstraction of hydrogen from the selected site of the molecule; - inject or remove electrons from the surface intermediates by providing high density of states at the energy level corresponding to the C-H redox potential; - perform nucleophilic addition of a surface oxide ion of high enough basicity, which could be easily extracted from the surface in the desorption step of the oxygenated intermediate, e.g. by crystallographic shear mechanism; - enable rapid diffusion of hydrogen and its desorption as water; - easily reoxidize by interaction with gas phase oxygen.