Zeolites are aluminosilicate materials whose nanoporous structure leads to wide application as shape-selective catalysts, catalytic supports and separation materials across multiple chemical industry sectors. Catalytic activity occurs at either incorporated metal centres or at framework Brønsted acid sites in the case of protonated zeolites. These applications depend on the complex geometric and chemical properties of the zeolite pore network, dictating how molecules adsorb into and diffuse through the material. Studying the chemistry and interactions of molecules in zeolites on timescales relevant to their diffusion and reaction is critical for developing an improved understanding of the many mechanisms of catalysis in these important materials.