A5020133473- Catalytic Processes in Materials Science
- Catalysts for Methane Reforming
- Catalysis and Oxidation Reactions
- Radioactive element chemistry and processing
- Carbon dioxide utilization in catalysis
- CO2 Reduction Techniques and Catalysts
- Radioactivity and Radon Measurements
- Mesoporous Materials and Catalysis
- Laser-Ablation Synthesis of Nanoparticles
- Chemical Synthesis and Characterization
- Electrocatalysts for Energy Conversion
- Chemical Looping and Thermochemical Processes
- Electrospun Nanofibers in Biomedical Applications
- Hydrogen Storage and Materials
- Nanoparticles: synthesis and applications
- Thermodynamic and Structural Properties of Metals and Alloys
- Polymer Surface Interaction Studies
- Molten salt chemistry and electrochemical processes
- Electrophoretic Deposition in Materials Science
- Radioactive contamination and transfer
- Organometallic Complex Synthesis and Catalysis
- Advanced Thermoelectric Materials and Devices
- Thermal and Kinetic Analysis
- Catalysis and Hydrodesulfurization Studies
University of Lisbon
2013-2024
Instituto de Engenharia de Sistemas e Computadores Investigação e Desenvolvimento
2016
Instituto Superior Técnico
2012-2013
Abstract The partial oxidation of methane (POM) was studied over bimetallic nickel‐ f block element oxide nanocatalysts prepared by a modified sol‐gel method. They proved to be active (conversion methane, 50–70%) at relatively low temperatures (550 and 650 °C) highly selective towards synthesis gas production (selectivity, H 2 60–90% CO 50–80%). activity selectivity depend on the surface basicity size nanoparticles: lower particle higher basicity, enhanced gas. Catalysts reducibility seems...
Abstract Cobalt‐lanthanide bimetallic oxide nanofibers (5Co 3 O 4 .3LnCoO , Ln=La, Pr; 4Co .Ln 2 Ln=Sm, Gd, Dy, Yb and 2Co .CeO ) were prepared by electrospinning technique for the first time evaluated as catalysts hydrogenation of CO . Depending on lanthanide, reaction products are different: lighter lanthanides (La, Pr, Sm Gd) produce mainly more active to reverse water gas shift (RWGS), whereas with Ce, Dy selective methane. Lanthanide intrinsic properties such ionic radii basicity...
For the first time, bimetallic copper–thorium (Cu–Th–O), nickel–thorium (Ni–Th–O), and nickel–uranium (Ni–U–O) oxides were tested for conversion of methane using N2O as oxidant. The behavior uranium thorium catalysts is very different: at 10% isoconversion (700 °C), production C2 hydrocarbons high over catalyst (≈80%), but formation oxidation products (CO2, CO) prevails thorium-based (≈85 ≈15% selectivity to COx C2). At higher temperature (750 remains (conversion CH4 ≈ 20%, 60%), syngas now...
Root extracts from Danube Delta Nymphaea alba were used to prepare gold nanoparticles (AuNPRn) by reducing HAuCl4 at different pHs (6.4-8.4) using ultrasonic irradiation: an easy, cheap, eco-friendly and green approach. Their antibacterial anticancer activities evaluated against Staphylococcus aureus Escherichia coli, A2780 ovarian cancer cells, respectively. The AuNPRn characterized concerning their phytoconstituents (polyphenols, flavonoids condensed tannins) content. All of the negatively...
The hydrogenation of CO2 is an important reaction aimed at, among other chemicals, synthetic methane production. Herein, we report the preparation and characterization affordable cobalt-lanthanide bimetallic oxide nanofibers cobalt-supported catalysts, using lanthanide as supports their catalytic behavior for methanation CO2. best results were those obtained over catalysts cerium ytterbium supports. These stand out with activity per cobalt square meter far superior to that measured a noble...
Cerium-based bimetallic oxides of the type 3NiO·CeO2, Co3O4·CeO2, and 1.5Fe2O3·CeO2 were prepared by two sol–gel methods (epoxide addition Pechini methods) electrospinning technique, aiming at synthesis compounds with different morphologies (nanoparticles or nanofibers) evaluation as catalysts for methanation CO2. The results obtained show a catalytic performance that depends on d block element, method, catalyst morphology. Regardless such parameters, best those over nickel-based technique...
High surface area cobalt-lanthanide bimetallic aerogels were successfully synthesized by the epoxide addition method. The calcined at two different temperatures and either oxides containing oxychlorides, Co3O4.3LnOCl (Ln = La, Sm, Gd, Dy Yb) or perovskites, LnCoO3 Gd Dy) obtained 500 900 °C, respectively. exceptions are of cerium ytterbium, which after oxidation stabilize as sesquioxides: Co3O4.3CeO2 2Co3O4.3Yb2O3, first both second only highest temperature. oxychlorides perovskites tested...
Abstract Nanostructured Cobalt‐Actinide (An=Th, U) bimetallic oxides were for the first time prepared by epoxide addition method and electrospinning technique aiming synthesis of aerogels nanofibers, respectively. Tested as catalysts methanation CO 2 regardless actinide element, yield selectivity towards CH 4 are high (>40 95 %, respectively), which was explained their physicochemical properties such reducibility basicity existence a synergic effect between cobalt species. The present...
THe methanation of carbon dioxide was studied over bimetallic nickel‐5 f block element oxides, 2NiO · ThO 2 and UO 3 . The catalysts were prepared by two approaches: controlled oxidation under dry air using intermetallic binary compounds (AnNi ; An=Th, U) as precursors a modified sol‐gel method. best results those obtained the thorium‐based that present activities selectivities higher than measured reference catalysts. To our knowledge, this is one few times oxides tested for their behaviour...