In the present study, the catalytic activity of palladium oxide (PdO_x) supported on ceria nanorods (CeO₂-NR) for aerobic selective oxidation of benzyl alcohol (BnOH) to benzaldehyde (PhCHO) was evaluated. The CeO₂-NR was synthesized hydrothermally and the Pd(NO₃)₂ was deposited by a wet impregnation method, followed by calcination to acquire PdO_x/CeO₂-NR. The catalysts were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR), transmission electron microscopy (TEM), Brunauer–Emmet–Teller (BET) surface area analysis, and X-ray photoelectron spectroscopy (XPS). In addition, the TPR-reduced PdO_x/CeO₂-NR (PdO_x/CeO₂-NR-Red) was studied by XRD, BET, and XPS. Characterizations showed the formation of CeO₂-NR with (111) exposed plane and relatively high BET surface area. PdO_x (x > 1) was detected to be the major oxide species on the PdO_x/CeO₂-NR. The activities of the catalysts in BnOH oxidation were evaluated using air, as an environmentally friendly oxidant, and various solvents. Effects of temperature, solvent nature and palladium oxidation state were investigated. The PdO_x/CeO₂-NR showed remarkable activity when protic solvents were utilized. The best result was achieved using PdO_x/CeO₂-NR and boiling ethanol as solvent, leading to 93% BnOH conversion and 96% selectivity toward PhCHO. A mechanistic hypothesis for BnOH oxidation with PdO_x/CeO₂-NR in ethanol is presented.

New dihydroxytyrosyl esters 2a, 2c–2j of dicarboxylic acids were synthesized from methyl orthoformate protected hydroxytyrosol 3 and diacyl chlorides. New compounds were characterized (HRMS, FT-IR, ¹H- and ¹³C-NMR), and tested for antioxidant activity both in vitro (ABTS) and on L6 myoblasts and THP1 leukemic monocytes cell culture by DCF assay. According to the ABTS assay, compounds 2a, 2c–2j showed a TEAC value of antioxidant capacity up to twice that of Trolox. Very high or complete ROS protections were obtained in the cell environment where lipophilicity and rigidity of dicarboxylic structure seem to facilitate the antioxidant effect. MTT assay and proliferation test were used for assessment of cell viability. These compounds can be envisaged as a new class of preservatives for food or cosmetic products.

Catalytic aerobic oxidation of benzyl alcohol (BnOH) to benzaldehyde (PhCHO) over supported noble metal catalysts has grabbed the attention of researchers due to the critical role of PhCHO in numerous industrial syntheses. In the present study, a novel catalyst, Pd-P alloy supported on aminopropyl-functionalized mesoporous silica (NH₂-SiO₂), was prepared through in situ reduction and characterized by BET-BJH analysis, SEM, TEM, XRD, FTIR, TG-DTA, and XPS. Chemical properties and catalytic performance of Pd-P/NH₂-SiO₂ were compared with those of Pd° nanoparticles (NPs) deposited on the same support. Over Pd-P/NH₂-SiO₂, the BnOH conversion to PhCHO was much higher than over Pd°/NH₂-SiO₂, and significantly influenced by the nature of solvent, reaching 57% in toluene at 111 °C, with 63% selectivity. Using pure oxygen as an oxidant in the same conditions, the BnOH conversion increased up to 78%, with 66% selectivity. The role of phosphorous in improving the activity may consist of the strong interaction with Pd that favours metal dispersion and lowers Pd electron density.

Benzyl alcohol (BnOH) oxidation to benzaldehyde (PhCHO) is a pivotal industrial reaction. The aerobic oxidation of BnOH in solvent-free conditions is highly compatible with the necessity of low environmental impact. In this research work, palladium oxide (PdO_x) supported on ceria nanorods (CeO₂-NR), was synthesized, and utilized for aerobic solvent-free oxidation of BnOH derivatives to the corresponding aldehydes. The catalyst, PdO_x/CeO₂-NR, was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy/energy-dispersive spectroscopy (FE-SEM/EDS), N₂ adsorption-desorption analysis, temperature-programmed reduction with hydrogen (H₂-TPR), and X-ray Photoelectron Spectroscopy (XPS), proving that the PdO_x (x > 1) particles were highly dispersed on CeO₂-NR and have a strong interaction with the support. The PdO_x/CeO₂-NR catalyst permitted the aerobic oxidation of various benzyl alcohol derivatives with good conversion, and high selectivity towards the corresponding aldehydes. The presence of electron donating groups (EDG) on the benzylic ring enhanced the reactivity as opposed to the electron withdrawing groups (EWG) which were detrimental for the catalytic activity. During the reaction a partial reduction of the metal produced a Pd(0)/PdO_x/CeO₂-NR redox couple stable in the reaction condition, more reactive and recyclable. Some mechanistic hypotheses are presented.

The use of efficient solar ovens can be a way for progressing ecofriendly technologies in the field of food preparation. In most performing direct solar ovens, the sun rays reach the foods directly, therefore, it becomes essential to check whether, in these conditions, foods can retain theirnutraceutical properties (antioxidants, vitamins and carotenoids). In the present research work, to investigate this issue, several foods (vegetables, meats, and a fish sample) were analyzed before and after cooking (traditional oven, solar oven, and solar oven with a UV filter). The content of lipophilic vitamins and carotenoids (analyzed via HPLC-MS) and the variation of total phenolic content (TPC), and antioxidant capacity (via Folin–Ciocalteu and DPPH assays) have evidenced that cooking with the direct solar oven allows to preserve some nutrients (i.e., tocopherols) and, sometimes, to enhance nutraceutical properties of vegetables (for example, solar oven-cooked eggplants showed 38% higher TPC compared to electric oven cooked sample) and meats. The specific isomerization of all-trans-β-carotene to 9-cis was also detected. The use of a UV filter is advisable to avoid UV drawbacks (for instance, a significant carotenoid degradation) without losing the beneficial effects of the other radiations.

Background/Objectives: Recycling is an option for municipal and industrial waste management. Recycling not only helps the industry to reduce environmental pollution, it allows production of raw materials from useful waste for a wide variety of products. This study recycled cellulose from Calotropisgigantea fibers as a useful material in nature. Methods/ Statistical Analysis: Enzymatic hydrolysis as an eco-friendly process is used for recycling fiber by cellulase and betaglucosidase enzymes at pH=4.8 and 45°C and 24, 48, 72, 84 and 96 hours. The ability of these enzymes is evaluated for hydrolysis of cellulose and the effect of time on the progress of hydrolysis. The effect of alkaline pretreatment is evaluated on the efficiency of conversion of cellulose into glucose. Then, the sugar solution with the highest efficiency of hydrolysis was fermented by 15g/l commercial baker's yeast at 30°C for 72 hours and the result is measured. Findings: The best results are obtained by enzymatic hydrolysis of Calotropisgigantea fibers pretreated in the presence of both cellulase and beta-glucosidase for 84 hours. Applications/Improvements: Efficiency of both hydrolysis and fermentation is high for the pretreated Calotropisgigantea fibers and alkaline pretreatment multiplied the efficiency of hydrolysis.