The combination of X-ray photoelectron spectroscopy (XPS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) allowed a clear identification and quantification of nitrogenous species incorporated upon nitridation in three different zeolites one Y zeolite (Si/Al ratio of 2.6) and two ultrastable Y zeolites (Si/Al ratios of 13 and 37). Both the amount and the chemical nature of incorporated nitrogen species were controlled by the nitridation temperature. Namely, an increase of the temperature induces an increase of the nitrogen content and the appearance of nitrogenous species in the following order of increasing temperature: NH4 +, adsorbed NH3, −NH2, >NH, and >N−. Based on these spectroscopic results, a mechanism of nitridation in function of temperature was proposed, this mechanism being independent of the properties of the parent zeolite. We evidenced here that the replacement of hydroxyls groups located in the microposity of the zeolite by nitrogen species was effective which can be very motivating result for the application of these materials as shape selective catalysts.

This contribution reports on the preparation, physicochemical characterization and catalytic performances of nitrided zeolites in the Knoevenagel condensation reaction. These basic materials were prepared by subjecting one Y zeolite (Si/Al ratio of 2.6) and two ultrastable Y zeolites (Si/Al ratio of 13 and 37) to nitridation, i.e., treatment with ammonia at high temperature. Both the amount and the chemical nature of incorporated nitrogen species were controlled by the nitridation temperature. Namely, an increase of the temperature induces an increase of the nitrogen content and the appearance of nitrogenous species in the following order of increasing temperature: NH 4 ? , adsorbed NH 3 , -NH 2 , [NH and [N-. The nitridation occurred practically in the same manner whatever the Si/Al ratio of the starting material. However, from a catalytic point of view different behavior was observed. No direct correlation was found with the nitrogen content of the samples. Nitrided zeolites were found to exhibit catalytic activity as long as the zeolitic framework was maintained.

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Essential oils (EOs) are used in medicinal, pharmaceutical, cosmetic, agricultural, and food industries thanks to their key properties and multiple benefits. Several techniques and embedding materials are used to nanoencapsulate EOs, in order to keep them from environmental conditions and boost their bioefficiency by controlled release. In recent years, the interest for clay nanoparticles as nanoencapsulation materials for EOs is increasing owing to their abundance in nature, low cost, inertness, and special structure. Thus, this chapter focuses on highlighting data and contributions dealing with EOs incorporation into nanoclay particles, their current applications and nanohybrid formation benefits on the stability, bioavailability, and sustained release of EOs. An overview about nanoclays used for EOs nanoencapsulation is highlighted in the beginning of this chapter followed by a brief description of EOs’ chemical composition and properties.