Key ingredients in solid-state electrochemistry are charge transfer to, and adsorption/reaction of molecules, both heavily influenced by the availability of charge carriers and O vacancies. Surface science techniques, in particular Scanning Tunneling Microscopy (STM) in combination with surface spectroscopy, can help unravel how these processes happen at the atomic scale. The talk will showcase several examples of STM studies of adsorption and reaction of O₂ and H₂O on titania and selected perovskite materials. It will also exemplify how STM can be used to judiciously steer thin film growth in in Pulsed Laser Deposition (PLD) towards fabricating model electrodes with a desired surface structure, which could help increasing functionality in electrochemical devices.