With the ubiquity of catalysts in industrial processes for chemical, fuel, polymer, and pharmaceutical production, catalyst design that limits deactivation and improves efficacy (in terms of mass transfer artifacts and/or selective conversions) can decrease process energy demands. Our work focuses on porous crystalline materials such as zeolites and metal-organic frameworks (MOFs), where it is important to define active sites, to probe influences of transport, and to incorporate deactivation and materials stability. In the case of zeolites, incorporation of mesopores into bulk microporous frameworks is one route to alter mass transfer, particularly of bulky molecules. Here, we probe the condensed-phase hydrocarbon conversions (aromatics and waste polyolefins) on various microporous and hierarchical zeolites to deduce diffusional effects on rates, selectivities, and stability using kinetic analyses and observed changes in reaction and deactivation rates. In the case of MOFs, the less hydrothermally stable counterpart to zeolites, we delineate structural and reaction stability during liquid-phase reactions, specifically over the Cr and Fe variants of MIL-101 for styrene oxidation by hydrogen peroxide. Overall, we demonstrate that deactivation phenomena limit catalyst efficiencies in both zeolitic and MOF reaction systems but can be alleviated through synthetic and reaction modifications, which has broad implications for these and other industrial catalytic systems.