​Multiphase catalytic processes involve the combination of scale-dependent and scale-independent phenomena, often resulting in a compromised, sub-optimal performance. The classical approach of randomly packed catalyst beds using unstructured catalyst particles may be outperformed by the careful design of the catalyst at the nano-scale and by the judicious choice and design of reactor. Application of structured catalysts and reactor internals and the combination of advanced reactor and catalyst systems with in situ separation allow decoupling the various phenomena involved, opening the way to intensified processes on a large scale. The integral approach of Catalysis and Reaction Engineering discussed here will play a pivotal role in the development of novel, future-proof processes.