The research area of catalysis engineering is bringing together the fields of Reactor Engineering and Catalysis. For optimal performent, a state-of-the-art-catalyst requires a state-of-the-art-reactor, and vice versa. Understanding both the catalyst and the processes occurring in the chemical reactor, it will be possible to develop the most efficient system. Especially in a reaction system in which not only the desired reaction but also competing reactions occur (causing a loss in selectivity or a deactivation of the catalyst), understanding the entire system is crucial. An optimal design of the catalyst-reactor system will only be possible by optimizing all the relevant length scales, from the site of the catalyst, to the mass transfer length in the catalyst, to the catalyst particle size and shape (determining the external mass transfer), and the macromixing behavior in the reactor (determining the local environment of the catalyst). Within this research area, we convert the reactor concepts of rotating reactors and microreactors from the other research lines into catalytic reactors. We perform kinetic and mass transfer measurements on these catalytic systems to improve the understanding of both the catalyst and reactor and to be able to model their performance.