The chemical industry is one of the pillars of the Flemish economy. It converts raw materials such as oil and natural gas into more than 70,000 products. Catalysis plays a key role in this industry, and more than 90% of the products are made in catalytic processes. The most important property of a catalytic process is selectivity. Indeed, increasing selectivity minimizes both energy consumption and waste production. In this project we develop a novel modelling-guided approach to design catalysts with optimal selectivity. To achieve breakthroughs in catalyst design, catalytic reaction mechanisms need to be understood and controlled at the scale of the active sites, the molecular scale.