A catalyst is a material that facilitates a chemical reaction. It allows for a more environmentally friendly production of chemicals. Since catalysis usually happens at the surface of materials, the maximization of surface area is paramount. In this respect, extremely small nanocrystals are very promising since they feature a strikingly high surface/volume ratio and therefore many different catalyst materials were synthesized as nanocrystals (i.e., the nanocrystal library). However, to maintain the very small size of the nanocrystals, defense molecules are present on the surface. Unfortunately, these defense molecules also inhibit the accessibility of the surface for catalysis, thereby placing a lock on the nanocrystal library. In this project, we will therefore gain fundamental knowledge of the nanocrystal surface chemistry to unlock the nanocrystal library for catalysis. Our strategy is twofold. On the one hand we will device catalytic systems where the defense molecules are also the reagent in the envisaged chemical reaction. On the other hand we seek to form porous, self-supporting macrostructures of nanocrystals (i.e., aerogels), with very high surface areas due to a controlled aggregation of the nanocrystals. In conclusion, this work will be the frontrunner of a novel direction in nano-catalysis and provide the necessary insights for a real breakthrough to more active and re-usable catalysts