Methane, discovered in 1766 by Alessandro Volta, is an attractive energy source because of its high heat of combustion per mole of carbon dioxide. However, methane is the most abundant hydrocarbon in the atmosphere and is an important greenhouse gas, with a 21-fold greater relative radiative effectiveness than CO₂ on a per-molecule basis. To avoid or limit the formation of pollutants that are dangerous for both human health and the atmospheric environment, the catalytic combustion of methane appears to be one of the most promising alternatives to thermal combustion. Total oxidation of methane, which is environmentally friendly at much lower temperatures, is believed to be an efficient and economically feasible way to eliminate pollutants. This work presents a literature review, a statu quo, on catalytic methane oxidation on transition metal oxide-modified ceria catalysts (MO_x/CeO₂). Methane was used for this study since it is of great interest as a model compound for understanding the mechanisms of oxidation and catalytic combustion on metal oxides. The objective was to evaluate the conceptual ideas of oxygen vacancy formation through doping to increase the catalytic activity for methane oxidation over CeO₂. Oxygen vacancies were created through the formation of solid solutions, and their catalytic activities were compared to the catalytic activity of an undoped CeO₂ sample. The reaction conditions, the type of catalysts, the morphology and crystallographic facets exposing the role of oxygen vacancies, the deactivation mechanism, the stability of the catalysts, the reaction mechanism and kinetic characteristics are summarized.

Over the past several decades, an increasing amount of attention has been given to catalytic combustion as an environmentally friendly process. However, major impediments to large-scale application still arise on the materials side. Here, we review catalytic combustion on thin film catalysts in view of highlighting some interesting features. Catalytic films open the way for new designs of structured catalysts and the construction of catalysts for catalytic combustion. A special place is occupied by materials in the form of very thin films that reveal catalytic activity for various chemical reactions. In this review, we demonstrate the high catalytic activity of thin film catalysts in these oxidation reactions.

In the current study, ZnO nanoparticles were obtained using a chemical process employing zinc acetate as the precursor, followed by thermal processing in air. To prevent agglomeration and increase the stability of ZnO nanoparticles, two unsaturated acids (e.g., elaidic acid and linoleic acid) and two saturated acids (e.g., stearic acid and lauric acid) were selected as capping agents. ZnO nanoparticles were investigated before and after surface modification with different fatty acids. Structural and morphological analyses of the samples were performed using FTIR and RAMAN spectroscopy, X-ray diffraction, SEM microscopy, and wetting capacity. Characterization studies revealed that the synthesized ZnO nanoparticles present well-defined crystalline structures, with crystallite sizes varying between 26 and 28 nm, and the average particle size was in the range of 10–55 nm (depending on the type of fatty acids used). The goniometric analysis followed the wetting capacity of the sample surface. The study results reveal that the capping agents have a considerable impact on the surface modification of the nanoparticles by increasing the contact angle. By producing nanoparticles with hydrophobic behavior, there is the possibility of opening up future research for their use in various applications across many industrial fields.

Clove essential oil (Eugenia caryophyllata essential oil, ECEO) is known for its high eugenol content and notable antimicrobial properties. However, the volatility and instability of its active compounds hinder broader pharmaceutical applications. Methods: This study characterised the chemical composition of ECEO and comparatively evaluated four β-cyclodextrin (β-CD) encapsulation methods: kneading, co-precipitation, lyophilisation, and co-precipitation–lyophilisation for eugenol, eucalyptol, and ECEO. Encapsulation efficiency, physicochemical properties, and antimicrobial potential were assessed. Analytical techniques included Gas Chromatography–Mass Spectrometry (GC-MS), Headspace GC-MS (HS-GC-MS), Differential Scanning Calorimetry (DSC), Job’s method, and Dynamic Light Scattering (DLS). Results: GC-MS identified eugenol (90.67%), eugenyl acetate (4.77%), and (E)–β-caryophyllene (3.98%) as major components of ECEO, while HS-GC-MS indicated a slightly reduced eugenol content (86.46%). The kneading method yielded the highest encapsulation efficiency for eugenol, whereas the co-precipitation–lyophilisation method was optimal for eucalyptol. DSC thermograms confirmed complex formation, and DLS analysis revealed nanostructures averaging 186.4 nm in diameter (PDI = 0.298). Antimicrobial assays showed MIC values ranging from 0.039 mg/mL to 10,000 mg/mL. Notably, ECEO and its β-CD complex displayed enhanced efficacy against Escherichia coli (0.039 mg/mL), surpassing the reference antibiotic gentamicin (0.049 mg/mL). Conclusions: β-Cyclodextrin encapsulation significantly enhances the stability and bioactivity of volatile antimicrobial compounds, thereby supporting their potential integration into advanced essential oil-based pharmaceutical formulations.