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.
PdxNiy/TiO2 Electrocatalysts for Converting Methane to Methanol in An Electrolytic Polymeric Reactor - Fuel Cell Type (PER-FC)
2023 - COELHO, JESSICA F.; GUTIERREZ, ISABELY M.; PEREIRA FILHO, NIVALDO G.; ZAMBIAZI, PRISCILLA J.; OLIVEIRA NETO, ALMIR; SOUZA, RODRIGO F.B. de
PdxNiy/TiO2 bimetallic electrocatalysts were used in fuel cell polymeric electrolyte reactors (PER-FC) to convert methane into methanol through the partial oxidation of methane promoted by the activation of water at room temperature. X-ray diffraction measurements showed the presence of Pd and Ni phases and TiO2 anatase phase. TEM images revealed mean particle sizes larger than those reported for PdNi materials supported, indicating that TiO2 promotes particle aggregation on its surface. Information on the surface structure of electrocatalysts obtained by Raman spectra indicated the presence or formation of NiO. The PER-FC tests showed the highest power density for the electrocatalyst with the lowest amount of nickel Pd80Ni20/TiO2 (0.58 mW cm􀀀2). The quantification of methanol through the eluents collected from the reactor showed higher concentrations of methanol produced, revealing that the use of TiO2 as a support also increased the reaction rate.
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.
Conversion of nitrogen to ammonia using a Cu/C electrocatalyst in a polymeric electrolyte reactor
2023 - MAIA, VICTORIA A.; SANTOS, CAMILA M.G.; AZEREDO, NATHALIA F.B.; ZAMBIAZI, PRISCILLA J.; ANTOLINI, ERMETE; NETO, ALMIR O.; SOUZA, RODRIGO F.B. de
The electrochemical conversion of N2 to NH3 using a polymeric electrolyte reactor is a promising method to accelerate the green production of hydrogen carriers. On this basis, we report the efficiency of ammonia production by the nitrogen reduction reaction using a Cu/C catalyst in a polymeric electrolyte membrane reactor. The Cu/C catalyst was prepared by the NaBH4 reduction method and characterized by X-ray diffraction, transmission electron microscopy, cyclic voltammetry, and conversion experiments performed in a polymer electrolyte membrane fuel cell type reactor. The X-ray diffraction results showed the presence of CuO2 and carbon phases, while the TEM images showed a high agglomeration of copper nanoparticles on carbon. The onset potential of nitrogen reduction was near to the Cu (I) to Cu0 reduction peak. Mass spectroscopy was used to observe the production of N2H2 and NH3 and the consumption of N2. Maximum ammonia production was detected at 0.0 V with a NH3 yield rate of 38.4 µg h−1 cm−2 and a faradaic efficiency of 42.57 %.
Methane‑to‑methanol conversion and power co‑generation on palladium
2022 - COELHO, JESSICA F.; FILHO, NIVALDO G.P.; GUTIERREZ, ISABELY M.; GODOI, CAMILA M.; GOMES, PAULO V.R.; ZAMBIAZI, PRISCILLA J.; SOUZA, RODRIGO F.B. de; NETO, ALMIR O.
The use of palladium nickel catalysts with different compositions supported metal oxides, such as Sb2O5·SnO2 (ATO) catalyst combinations were employed to convert the methane-to-methanol in mild conditions using a fuel cell polymer electrolyte reactor. The catalysts used for the conversion of methane to methanol were characterized by XRD and observed the phases of ATO, the face-centered cubic structure of the Pd and Ni phases. All nanoparticles have a mean size between 9 and 12 nm as measured by TEM images. The products obtained from the methane oxidation, such as methanol and formate, were monitored using FT-IR spectroscopy to qualify the products formation, while High-Performance Liquid Chromatography was used to quantify them. In these studies, it was observed that as the electrical potential of the reactor increases, the generation of products decreases. The best results for the conversion of methane into methanol and energy co-generation were obtained from Pd50Ni50/ATO.
Production of methanol on PdCu/ATO in a polymeric electrolyte reactor of the fuel cell type from methane
2022 - GODOI, CAMILA M.; GUTIERREZ, ISABELY M.; GOMES, PAULO V.R.; COELHO, JESSICA F.; ZAMBIAZI, PRISCILLA J.; OTUBO, LARISSA; NETO, ALMIR O.; SOUZA, RODRIGO F.B. de
The search for alternatives for converting methane into value-added products has been of great interest to scientific, technological, and industrial society. An alternative to this could be the use of copper-doped palladium catalysts with different proportions supported on metal oxides, such as Sb2O5.SnO2 (ATO) catalysts. These combinations were employed to convert the methane-to-methanol in mild condition using a fuel cell polymer electrolyte reactor. The catalysts prepared presents Pd, CuO, and Sb2O5.SnO2 phases with a mean particle size of about 9 nm. In activity experiments, the Pd80Cu20/ATO indicated maximum power density and maximum rate reaction for methanol production when compared to other PdCu/ATO materials. The use of ATO as a support favored the production of methanol from methane, while PdCu with high copper content demonstrated the production of more oxidized compounds, such as carbonate and formate.
Methanol electrosynthesis from CO2 reduction reaction in polymer electrolyte reactors - fuel cell type using [6,6′-(2,2′-bipyridine-6,6′-diyl)bis(1,3,5-triazine-2,4-diamine)] (dinitrate-O) copper (II) complex
2022 - GARCIA, L.M.S.; FILHO, N.G.P.; CHAIR, K.; KAUR, P.; RAMOS, A.S.; ZAMBIAZI, P.J.; SOUZA, R.F.B. de; OTUBO, L.; DUONG, A.; NETO, A.O.
Electrocatalytic carbon dioxide reduction reaction has been an attractive way to convert greenhouse gas into valuable chemical fuels based on carbon-neutral energy. Therefore, it serves as an effective approach to combating high concentrations of CO2 in the atmosphere as well as reducing the use of fossil fuels responsible for emitting carbon dioxide and other greenhouse gases, meeting growing energy demands. In this work, the copper(II) bis-triazine bipyridine complex supported on carbon black has been applied as a catalyst in a polymeric electrolytic reactor – fuel cell type for converting CO2 into methanol. The physical and nanostructure properties of the Cu(II) nanocomposite were previously determined by Fourier transform infrared, Raman spectroscopy, X-ray powder diffraction, and transmission electron microscopy techniques. The electrocatalytic activity of the Cu complex catalyst was monitory by differential mass spectroscopy. The results indicate that the catalyst is not selective for the preferential synthesis of a specific product, but a mixture of products (methanol, formic acid, formaldehyde, carbon monoxide, and methane) was detected. According to our results, 2.5% and 5% Cu complex on carbon black were the ideal amounts for polymeric electrolytic reactor – fuel cell type applications to produce methanol from CO2 with faradaic efficiency of ∼22% for both compositions.
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.
PtSb/C electrocatalysts for glycerol oxidation in alkaline electrolyte
2022 - PEREIRA, C.V.; MAIA, V.A.; ZAMBIAZI, P.J.; SOUZA, R.F.B. de; ANTOLINI, E.; NETO, A.O.
Pt/C and PtSb/C catalysts in various atomic ratios were synthesized by the sodium borohydride reducing method and their activity for the glycerol oxidation reaction (GOR) was evaluated in alkaline media. Transmission Electron Microscopy (TEM) images showed that Pt particle size increases with increasing Sb content in the catalyst. X-ray photoelectron spectroscopy (XPS) showed that the ratio of Pt and Sb is close to that expected. By XPS measurements, the presence of Sb2O5 in Pt70Sb30/C and Pt50Sb50/C was observed. X-ray diffraction (XRD) analysis revealed the presence of the face-centered cubic (FCC) structure of Pt and PtSb and of some others phases that could be identified as Sb oxides. By linear sweep voltammetry (LSV) measurements, Pt80Sb20/C showed the highest activity for the GOR in alkaline media for potentials >−0.35 V vs. Ag/AgCl, while Pt50Sb50/C showed the highest GOR activity in the potential range between −0.60 and −0.35 V vs. Ag/AgCl. The direct glycerol fuel cells with Pt80Sb20/C as the anode catalyst showed the best performance. These results attest the beneficial effect of Sb addition to platinum: the activity enhancement in the presence of Sb atoms has to be ascribed to both a bifunctional mechanism related to the presence of Sb oxides, and an electronic effect between platinum and antimony in the PtSb alloy.