Book excerpt: Heterogeneous catalysis is a key element in a global energy strategy that enables a lower energy route for the many chemical reactions essential to food production, fuels, pharmaceuticals, and other essential materials in our everyday lives. Modeling catalytic systems can inform the design of experiments, identify catalyst properties that optimize quantities-of-interest (QoI) for the discovery of new catalysts, and link catalyst properties to commercial reactor design. A comprehensive understanding of these reactions, achieved through multiscale modeling, is a vital step in establishing viable commercial processes. Additionally, a thorough understanding of the key elements comprising an effective model, efficiently and accurately parameterizing the model, and properly understanding and accounting for parametric uncertainty in models are essential for maximizing and quantifying the models' predictive ability.