Porous washcoat structure in CeO₂ modified Cu‐SSZ‐13 monolith catalyst for NH₃‐SCR with improved catalytic performance

Abstract

A series of CeO2 modified Cu‐SSZ‐13 monolith catalysts were prepared by embedding CeO2 into the washcoat of Cu‐SSZ‐13 monolith catalyst through solvent combustion method. These CexCu‐SSZ‐13 catalysts were studied in the selective catalytic reduction (SCR) of NO with NH3, among which the Ce2Cu‐SSZ‐13 catalyst exhibited the best low‐temperature activity, hydrothermal stability, and sulfur resistance. The physicochemical properties of the catalysts were characterized using multiple methods. Results showed that the acidity, redox capacity, and ammonia adsorption capacity significantly enhanced after CeO2 modification, thus leading to the high performance of Ce2Cu‐SSZ‐13 catalyst. Furthermore, the introduction of CeO2 induced the fast SCR reaction by promoting the oxidation of NO to NO2. Analog calculation suggested that the porous structure generated via solvent combustion in the washcoat effectively increased the diffusion rate of reaction. In situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFT) analysis showed that Brønsted acid sites were the main active center and the reaction followed Eley–Rideal mechanism.

Weakening Mn–O Bond Strength in Mn-Based Perovskite Catalysts to Enhance Propane Catalytic Combustion

“…The monolithic catalysts have always been required for practical application because of their advantages of a low pressure drop as well as good mass and heat transfer properties in actual industrial reaction units. , Hereby, we coated the preferred SN 0.10 M 0.90 catalyst on a cordierite honeycomb carrier using a wash-coating process to prepare the SN 0.10 M 0.90 /cordierite monolithic catalyst and evaluated its propane catalytic oxidation performance. As displayed in Figure d, it can be found that when the reaction temperature was <450 °C, the higher the H 2 O content of the feed gases is, the higher is the inhibition effect on the catalytic performance.…”