Part I: Introduction.- Bridging Materials and Pressure Gaps in Surface Science and Heterogeneous Catalysis.- Part II: Model Systems for Nanocatalysts to Bridge Materials Gap.- Shape-Controlled Nanoparticles: Effect of Shape on Catalytic Activity, Selectivity, and Long-term Stability.- Non-Colloidal Nanocatalysts Fabricated with Nanolithography and Arc Plasma Deposition.- Dendrimer Encapsulated Metal Nanoparticles: Synthesis and Application in Catalysis.- Core-Shell Nanoarchitectures as Stable Nanocatalysts.- Shape-Controlled Bimetallic Nanocatalysts in Fuel Cells: Synthesis and Electrocatalytic Studies.- Part III: In situ Surface Characterization to Bridge Pressure Gaps.- Role of Surface Oxides on Model Nanocatalysts in Catalytic Activity of CO Oxidation.- Influence of Atomic Structure, Steps and Kinks, on the Catalytic Activity: In situ Surface Studies.- The Development of Ambient Pressure X-Ray Photoelectron Spectros-Copy and its Application to Surface Science.- Electronic Excitations on Surfaces During Chemical and Photon Process.