24 documents found, page 1 of 3
From waste to value: electrocatalytic reduction of nitrate into ammonia at mono...
Ferreira, Marta; Kuzniarska-Biernacka, Iwona; Soares, Olívia S. G. P.; Figueiredo, José L.; Pereira, Manuel F. R.; Neves, Isabel C.; Fonseca, A. M.The electrochemical transformation of nitrate ions into ammonia (NH3), which ranks among the most widely employed chemicals globally, using mono (Pd, Pt) and bimetallic catalysts (Pd-Cu, Pt-Cu, Ru-Cu) supported on carbon nanotubes (CNT) was studied in acidic medium. The higher conversion and best selectivity towards NH3 corresponding, respectively, to 88 and 80% were found for Pt_CNT modified electrode, with an...
Optimization of iron-ZIF-8 catalysts for degradation of tartrazine in water by ...
Assila, Ouissal; Vilaça, Natália; Bertão, Ana R.; Fonseca, A. M.; Parpot, Pier; Soares, Olívia S. G. P.; Pereira, Manuel F. R.; Baltazar, FátimaOptimization of iron zeolitic imidazole framework-8 (FeZIF-8) nanoparticles, as heterogeneous catalysts, were synthesized and evaluated by the Fenton-like reaction for to degrade tartrazine (Tar) in aqueous environment. To achieve this, ZIF-8 nanoparticles were modified with different iron species (Fe2+ or Fe3O4), and subsequently assessed through the Fenton-like oxidation. The effect of different parameters su...
Degradation of pollutants in water by Fenton-like oxidation over LaFe-catalysts...
Assila, Ouissal; Barros, Óscar; Fonseca, A. M.; Parpot, Pier; Soares, Olívia S. G. P.; Pereira, Manuel F. R.; Zerrouq, Farid; Kherbeche, AbdelhakThe effect of different parameters such as temperature, type of catalyst and hydrogen peroxide (H2O2) concentration on the degradation of pollutants in water by Fenton-like oxidation was studied by using the Box-Behnken design (BBD), an effective statistical model to design the experiments. Concerning the heterogeneous catalysts, three bimetallic catalysts with lanthanum (La) and iron (Fe) ion-exchanged into ze...
Raw clays from Morocco for degradation of pollutants by Fenton-like reaction fo...
Assila, Ouissal; Bencheqroun, Zineb; Rombi, Elisabetta; Valente, Teresa Maria Fernandes; Braga, Amália S.; Zaitan, Hicham; Kherbeche, AbdelhakThree raw clays from Morocco were used as heterogeneous catalysts for Fenton-like oxidation of organic pollutants in water. The selected pollutants were two dyes used in the textile industry, Congo Red (CR) and Tartrazine (Tar, known also as a food coloring compound, E102) and Caffeine (Caf), a stimulant drug present in popular beverages such as coffee and tea, commonly used in Morocco. Two different processes ...
Fe(III)-exchanged zeolites as efficient electrocatalysts for Fenton-like oxidat...
Bencheqroun, Zineb; Sahin, Nihat E.; Soares, Olívia S. G. P.; Pereira, Manuel F. R.; Zaitan, Hicham; Nawdali, Mustapha; Rombi, ElisabettaElectrochemical oxidation, a powerful tool for the conversion of several of organic dye compounds using metal-exchanged zeolite modified electrodes, has shown great potential due to its capability of high efficiency degradation, a global priority for a sustainable environment. In this study, the role of the Fe(III)-exchanged-zeolite-modified electrodes using two different zeolite structures (such as FAU (Y) and...
Performance of self-cleaning cotton textiles coated with TiO2, TiO2-SiO2 and Ti...
Landi Jr, Salmon; Carneiro, Joaquim A. O.; Parpot, Pier; Soares, Olivia S. G. P.; Pereira, Manuel F. R.; Fonseca, António M.; Neves, Isabel C.In the present study composites based on TiO(2 )nanoparticles, SiO2 and HY zeolite were synthesized by using a standard sol-gel methodology and analyzed by Fourier-transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy-dispersive X-ray spectroscopy techniques. The photocatalysts were impregnated on cotton textiles and their photocatalytic abilities were examined by degradatio...
Fenton-type bimetallic catalysts for degradation of dyes in aqueous solutions
Santos, Bebiana L. C.; Parpot, Pier; Soares, Olívia S. G. P.; Pereira, Manuel F. R.; Rombi, Elisabetta; Fonseca, António; Neves, Isabel C.Dye compounds are becoming a problematic class of pollutants for the environment, so it is important to develop stable catalysts for their elimination. First, several studies were performed with different Y zeolites (NaY, (NH4)Y and USY) in order to select the best support for the preparation of the bimetallic catalysts. In particular, NaY zeolite was used as the support for Fe, Cu and Mn metals to prepare mono...
Electrochemical oxidation of amoxicillin on carbon nanotubes and carbon nanotub...
Ferreira, Marta; Kuzniarska-Biernacka, Iwona; Fonseca, António; Neves, Isabel C.; Soares, Olívia S. G. P.; Pereira, Manuel F. R.; Figueiredo, José L.The electrolysis of amoxicillin (AMX) was carried out on CNT, Pt/CNT and Ru/CNT modified electrodes based on Carbon Toray in 0.1 M NaOH, 0.1 M NaCl and 0.1 M Na2CO3/NaHCO3 buffer (pH 10) media with the aim of studying the significance of two factors, electrode material and pH, on the oxidative degradation and mineralization of AMX. For this purpose, the electrolysis products were identified by HPLC-MS and GC-MS...
Photocatalytic performance of N-doped TiO2nano-SiO2-HY nanocomposites immobiliz...
Landi Júnior, Salmon; Carneiro, Joaquim; Soares, Olivia S. G. P.; Pereira, Manuel F. R.; Gomes, Andreia C; Ribeiro, Artur; Fonseca, AntónioThis work reports the synthesis of nanocomposite photocatalytic materials based on nitrogen-doped TiO2nano, SiO2 and different percentages of HY zeolite (0, 12, 25 and 50%). These materials were characterized by using Fourier transformed infrared spectroscopy, X-ray diffraction, N2 adsorptiondesorption, UV-vis diffuse reflectance spectroscopy and scanning electron microscopy. The nanocomposites, which presented...
Encapsulation and characterisation of cationic benzo[a]phenoxazines in zeolite HY
Guney, Orhan; Gonçalves, M. Sameiro T.; Fonseca, António; Soares, Olívia S. G. P.; Pereira, Manuel F. R.; Neves, Isabel C.Different cationic fluorochromophores were sucessfully encapsulated by ship-in-the-bottle synthesis into supercages of zeolite HY. The cationic fluorochromophores are N-(5-amino-10-methyl-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium (1a), N-(10-methyl-5-(propylamino)-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium (1b), N-(5-(isopentylamino)-10-methyl-9H-benzo[a]phenoxazin-9-ylidene)ethanaminium (1c) and N1-((5-(i...