catalystcoated

Catalyst-coated refers to a surface or substrate onto which a catalytic material has been deposited to promote a chemical reaction. The coating provides the active sites for the reaction, while the underlying substrate offers mechanical support, porosity, or electrical or thermal pathways. Catalyst-coated materials are used where controlled, efficient reactions are needed and where bulk catalysts would be impractical.

Common substrates include ceramic or metallic monoliths, carbon papers or felts, porous metals, and membranes. The catalytic layer is typically a thin film, washcoat, or dispersed particles, often based on noble metals such as platinum, palladium, and rhodium, or on metal oxides and supported catalysts (for example, alumina, silica, or carbon supports). Coatings are designed to maximize surface area, optimize dispersion, and ensure adherence under operating conditions.

Manufacturing methods include washcoating, impregnation, spray or dip-coating, electroplating, chemical vapor deposition, atomic layer deposition, and formulation of catalyst inks followed by drying and calcination. The method chosen depends on the desired coating thickness, adhesion, temperature stability, and mass transfer characteristics.

Applications span automotive catalytic converters, where catalyst-coated monoliths reduce harmful emissions; fuel cells, with catalyst layers on gas diffusion layers; electrolysis, sensors, and various chemical reactors. Advantages of catalyst-coated designs include high active surface area, targeted catalyst use, and integration into flow geometries. Limitations involve potential issues with sintering, poisoning, thermal or mechanical degradation, and challenges in coating uniformity or recyclability.