CH4-SCR of NO over Co and Pd ferrierite catalysts: Effect of preparation on catalytic performance

Zeolite Properties, Methods of Synthesis, and Selected Applications

Zeolites, a group of minerals with unique properties, have been known for more than 250 years. However, it was the development of methods for hydrothermal synthesis of zeolites and their large-scale industrial applications (oil processing, agriculture, production of detergents and building materials, water treatment processes, etc.) that made them one of the most important materials of the 20th century, with great practical and research significance. The orderly, homogeneous crystalline and porous structure of zeolites, their susceptibility to various modifications, and their useful physicochemical properties contribute to the continuous expansion of their practical applications in both large-volume processes (ion exchange, adsorption, separation of mixture components, catalysis) and specialized ones (sensors). The following review of the knowledge available in the literature on zeolites aims to present the most important information on the properties, synthesis methods, and selected applications of this group of aluminosilicates. Special attention is given to the use of zeolites in agriculture and environmental protection.

Porous nanopeapod Pd catalyst with excellent stability and efficiency

Porous Pd@m-C/SiO₂ nanopeapods are prepared by a nanoconfinement method. The Pd nanoparticles show high efficiency and stability in chemical reactions such as reduction of nitrobenzene by H₂ and reduction of NO by NH₃. The high catalytic activity is attributed to the unique peapod structure, mesoporous wall, and large specific surface area on Pd@m-C/SiO₂ rendering the Pd nanoparticles highly active in chemical reactions.

Catalytic conversion of N2O over palladium catalysts based on dealuminated faujasite

Dealumination of the faujasite support was realised using a hydrothermal treatment at different temperatures (625 – 700°C). Then palladium catalysts were prepared by an ion exchange method. The prepared catalysts exhibited a high and constant activity up to 100% for N2O conversion. This performance was dependent on certain parameters, such as a high Si/Al ratio, the structural properties of the zeolitic support, and the metal function provided by the palladium. In addition, it is considered that the active sites in the reaction, which are suspected to be PdO, are influenced by the acidic properties of the support.