Ceramic catalysts can be categorized into several types based on their composition and structure: 1. Monolithic Catalysts: These are honeycomb-like structures that offer a large surface area and low pressure drop. 2. Pelletized Catalysts: These are small, spherical pellets that are used in packed bed reactors. 3. Foam Catalysts: These have a porous structure that allows for high gas flow and efficient reaction rates.