RODRIGO FERNANDO BRAMBILLA DE SOUZA

RODRIGO FERNANDO BRAMBILLA DE SOUZA

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Methane to methanol conversion using proton-exchange membrane fuel cells and PdAu/antimony-doped tin oxide nanomaterials
2023 - MAIA, VICTORIA A.; NANDENHA, JULIO; GONCALVES, MARLON H.; SOUZA, RODRIGO F.B. de; O.NETO, ALMIR
This study investigates the use of Au-doped Pd anodic electrocatalysts on ATO support for the conversion of methane to methanol. The study uses cyclic voltammetry, in situ Raman spectra, polarization curves, and FTIR analysis to determine the optimal composition of gold and palladium for enhancing the conversion process. The results demonstrate the potential for utilizing methane as a feedstock for producing sustainable energy sources. The Pd75Au25/ATO electrode exhibited the highest OCP value, and Pd50Au50/ATO had the highest methanol production value at a potential of 0.05 V. Therefore, it can be concluded that an optimal composition of gold and palladium exists to enhance the conversion of methane to methanol. The findings contribute to the development of efficient and sustainable energy sources, highlighting the importance of exploring alternative ways to produce methanol.
Conversão de metano em metanol com co-geração de energia elétrica a partir de catalisadores de paládio suportados em carbono
2023 - SILVA, ARACELI J.; ZAMBIAZI, PRISCILLA J.; GOMES, PAULO V.R.; NANDENHA, JULIO; GODOI, CAMILA M.; SOUZA, RODRIGO F.B. de; NETO, ALMIR O.; AZEREDO, NATHALIA F.B.
The application of solid electrolyte reactors for methane oxidation and energy co-generation is attractive, especially with the use of catalysts synthesized from noble metals such as palladium. In this work, we prepared three different compositions of palladium on carbon support to evaluate the composition that had the greatest potential for energy generation. Catalysts in the proportions of 5, 10 and 20% of Pd/C were tested for the conversion of greenhouse gases into organic molecules of higher added value using electrochemical fuel cell solid electrolyte reactors. The focus of this work was the conversion of methane into methanol, using the fuel cell as a reactor and the commercial Pd/C as electrocatalyst. The electrocatalysts were tested at the anode, analyzed by infrared (IR) spectroscopy and their activities verified by experiments with rotating ring disk electrode (RRDE). Higher levels of palladium (Pd/C 20%) favored obtaining electrical power, and the intermediate composition (Pd/C 10%) showed a greater production of less oxidized compounds, such as methanol, in addition to generating electricity.
Desempenho eletrocatalítico de Pd/C e Pt/C para geração de energia a partir do extrato de cana-de-açúcar em célula a combustível de líquido direto
2023 - VILLARDI, BRUNO D.Q.; FILHO, NIVALDO G.P.; GOMES, PAULO V.R.; NANDENHA, JULIO; GODOI, CAMILA M.; TAGOMORI, THAIS L.; AZEREDO, NATHALIA; SOUZA, RODRIGO F.B. de; NETO, ALMIR O.; ZAMBIAZI, PRISCILLA J.
The processing of biomass to obtain fuels such as ethanol results in generating waste and polluting the environment. However, to meet energy demand and simultaneously reduce environmental pollution, fuel cells are promising devices for converting chemical compounds into electricity. Fuel cells can be powered by various types of liquids, including the sugars available in sugarcane extract, with high energy potential. Fuel cells employ the use of noble metals as electrocatalysts, such as Pt or Pd, to carry out the oxidation of these fuels. In this sense, this work reports the study of the oxidation of sugarcane extract in these different noble metals. The platinum catalyst was shown to be more active for the oxidation of sugars, resulting in a power density 10 times greater than Pd/C using a 50% diluted sugarcane extract solution, resulting in promising fuel cell systems. To produce ecologically correct electrical energy for the industry in general.
cis-[6-(pyridin-2-yl)-1,3,5-triazine-2,4-diamine](dichloride) palladium(II)-based electrolyte membrane reactors for partial oxidation methane to methanol
2022 - GARCIA, LUIS M.S.; ZAMBIAZI, PRISCILLA J.; CHAIR, KHAOULA; DOAN, TUAN D.; RAMOS, ANDREZZA S.; NANDENHA, JULIO; SOUZA, RODRIGO F.B. de; OTUBO, LARISSA; DUONG, ADAM; NETO, ALMIR O.
Methane is an abundant resource and the main constituent of natural gas. It can be converted into higher value-added products and as a subproduct of electricity co-generation. The application of polymer electrolyte reactors for the partial oxidation of methane to methanol to co-generate power and chemical products is a topic of great interest for gas and petroleum industries, especially with the use of materials with a lower amount of metals, such as palladium complex. In this study, we investigate the ideal relationship between cis-[6-(pyridin-2-yl)-1,3,5-triazine-2,4-diamine(dichloride)palladium(II)] (Pd-complex) nanostructure and carbon to obtain a stable, conductive, and functional reagent diffusion electrode. The physical and structural properties of the material were analyzed by Fourier transform infrared (FT-IR) and Raman spectroscopies, transmission electron microscopy (TEM), and X-ray powder diffraction (XRD) techniques. The electrocatalytic activity studies revealed that the most active proportion was 20% of Pd-complex supported on carbon (m/m), which was measured with lower values of open-circuit and power density but with higher efficiency in methanol production with reaction rates of r = 4.2 mol L–1·h–1 at 0.05 V.
CO2 reduction on Cu/C used as a cathode in a polymeric electrolyte reactor
2022 - LIMA, MARIANA; GODOI, CAMILA M.; SANTOS, MONIQUE C.L.; NANDENHA, JULIO; NETO, ALMIR O.; SOUZA, RODRIGO F.B. de
CO2 is one of the leading greenhouse gases, so studies that turn this gas into higher value-added products, that function as simpler and cheaper hydrogen stores, as an alcohols, are extremely important. In this work we using a polymeric Electrolyte Reactor– fuel cell type supplied with H2 on platinum anode and dry CO2 in the cathode with a copper-carbon electrocatalyst. Copper nanoparticles supported on carbon Vulcan XC72 were produced by the sodium borohydride reduction method. The XRD revealed the presence of two different phases, CuO and Cu2O. In addition, the TEM images revealed agglomerates presence. The water, formaldehyde, methanol, methane, formic acid, dimethyl ether, oxalic acid, dimethyl carbonate, and ethylene-glycol were observed by differential mass spectroscopy on line with the reaction and the onset potential for each product and these results were confirmed by infrared spectroscopy – ATR-FTIR setup. This work showed the mapping CO2 reduced compounds for onset potential proposing some contributions to the literature.
Borohydride reduction method for PdIn/C electrocatalysts synthesis towards glycerol electrooxidation under alkaline condition
2021 - NANDENHA, JULIO; RAMOS, CARLOS E.D.; SILVA, SIRLANE G. da; SOUZA, RODRIGO F.B. de; FONTES, ERIC H.; OTTONI, CRISTIANE A.; OLIVEIRA NETO, ALMIR
Pd−In/C electrocatalysts were synthesized by the adapted borohydride reduction method in different atomic ratios. Electrocatalysts were evaluated by conventional electrochemical techniques and direct glycerol fuel cells. X-ray diffraction profiles indicated the structure of Pd and In (fcc) phases, as well as the presence of In higher oxidation states. Regarding Transmission electron microscopy, it showed the particle‘s average diameters between 6.1–12.7 nm. All PdIn/C electrocatalysts showed high current values for −0.30 V vs. Ag/AgCl, which the best one was PdIn/C 90 : 10. Higher performance for glycerol oxidation was observed in polarization curves at 90 °C for PdIn/C (30 : 70) composition.
High CO tolerance of Pt nanoparticles synthesized by sodium borohydride in a time-domain NMR spectrometer
2020 - RAMOS, A.S.; SANTOS, M.C.L.; GODOI, C.M.; QUEIROZ, L.C. de; NANDENHA, J.; FONTES, E.H.; BRITO, W.R.; MACHADO, M.B.; NETO, A.O.; SOUZA, R.F.B. de
The CO poisoning effect was overcome using a novel synthesis method. This method consists of using sodium borohydride reducing agent assisted by magnetic field and radiofrequency pulses in the time-domain NMR spectrometer. This synthesis was useful to disperse the Pt nanoparticles over the carbon support and to compress the lattice strain of the Pt crystalline structure. Besides that, Pt/C MFP90° showed a multi-CO oxidation component in cyclic voltammetry, and this can avoid the poisoning effect by creating a large availability of CO species to be adsorbed, desorbed, and re-adsorbed. Pt/C MFP90° has also shown the best performance in the PEMFC regarding H2 and CO + H2 experiments.
Estudo da oxidação de etanol sobre Pt usando ATR-FTIR em condições realistas de uma DEFC
2013 - OLIVEIRA NETO, ALMIR; NANDENHA, JULIO; LINARDI, MARCELO; SPINACE, ESTEVAM V.; SOUZA, RODRIGO F.B. de