Porous structures are important in catalysis for several reasons: - High Surface Area: The large surface area of porous materials allows for more active sites to be available for catalytic reactions. - Accessibility: The pores provide pathways for reactants to access the active sites, which is essential for the efficiency of the catalyst. - Stability: Many porous materials, such as zeolites and metal-organic frameworks (MOFs), are stable under a wide range of conditions, making them suitable for various catalytic processes.