ESTEVAM VITORIO SPINACE

Resumo

Possui graduação em Bacharel Em Química Com Atribuições Tecnológicas pela Universidade Estadual de Campinas (1988), mestrado em Química pela Universidade Estadual de Campinas (1991) e doutorado em Química pela Universidade Estadual de Campinas (1995). Atualmente é pesquisador do Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP. Tem experiência na área de Química, com ênfase em Catálise, atuando principalmente nos seguintes temas: eletrocatalisadores para celulas a combustível tipo PEMFC, catalisadores para a produção e purificação de hidrogênio. Bolsista de Produtividade em Desenvolvimento Tecnológico e Extensão Inovadora - DT. (Texto extraído do Currículo Lattes em 08 out. 2021)

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  • Artigo IPEN-doc 30352
    Methane conversion and hydrogen production over TiO2/WO3/Pt heterojunction photocatalysts
    2024 - CARMINATI, SAULO A.; JANUARIO, ELAINE R.; MACHADO, ARTHUR P.; SILVAINO, PATRICIA F.; VAZ, JORGE M.; SPINACE, ESTEVAM V.
    Along with the advantages of mild reaction conditions, simple operation, and low energy consumption, the photocatalytic conversion of methane in the presence of water presents great potential in facilitating direct methane conversion into value-added chemicals and H-2 generation. In this work, TiO2/WO3 heterojunction photocatalysts modified with Pt nanoparticles were synthesized and their performances towards methane conversion into ethane (C2H6) and hydrogen (H-2) in the presence of water were evaluated. The ternary photocatalysts were characterized by X-ray diffraction, UV-vis, scanning and transmission electron microscopy and X-ray photoelectron spectroscopy. The highly active TiO2/WO3/Pt photocatalyst achieved C2H6 and H-2 production rates of 1.18 mmol g(-1) h(-1) and 57 mmol g(-1) h(-1), respectively. These values were 37% (for C2H6) and 34% (for H-2) higher than those produced by a TiO2/Pt photocatalyst. The results show that the presence of WO3 in a very small concentration on TiO2 with the introduction of Pt as a co-catalyst contributes to achieving higher activities towards both C2H6 and H-2 evolution.
  • Artigo IPEN-doc 30270
    Catalisadores núcleo-casca com Pt-Ni embebidos em CeO2 para reações de reforma a vapor do etanol
    2023 - MORAES, TAMARA S.; PIAZZOLLA, FERNANDO; FIGUEIREDO, STEFANY S.; PAULA, DRYADE de; FONSECA, FABIO C.; SPINACE, ESTEVAM V.
    Catalisadores núcleo-casca, baseados em nanopartículas de níquel e platina em nanoesferas de sílica e cercadas por céria, foram testados para a reação de reforma a vapor de etanol (H2O/etanol: 3/1) a 673 e 773 K. Foram sintetizados 3 catalisadores com diferentes teores em massa de Ni (5 e 10%) e Pt (1 e 2%). Para o catalisador contendo 1% de Pt e 10% de Ni (1Pt10Ni-CS), o aumento da temperatura de reação de 673 para 773 K, acarretou em um aumento da estabilidade do catalisador e da seletividade a H2, CO e CO2. Diminuindo o teor de Ni no catalisador e aumentando o teor de Pt (2Pt5Ni-CS) houve aumento da estabilidade do catalisador, com a conversão se mantendo em 100% durante 20 h de reação. A forte capacidade redox da céria, juntamente com a mudança na estrutura do catalisador devido à deposição de óxido de cério juntamente com as patículas de Ni e Pt sobre as partículas SiO2, levou a uma excelente atividade e estabilidade desse catalisador para reação de reforma a vapor do etanol.
  • Artigo IPEN-doc 30182
    Methane conversion coupled with hydrogen production from water using Au/Ga2O3 photocatalysts prepared by different methods
    2023 - JANUARIO, ELAINE R.; CARMINATI, SAULO A.; TOFANELLO, ARYANE; SILVA, BRUNO L. da; SILVAINO, PATRICIA F.; MACHADO, ARTHUR P.; VAZ, JORGE M.; SPINACE, ESTEVAM V.
    Au/Ga2O3 photocatalysts were prepared by three different methods (pre-formed Au nanoparticles, borohydride reduction, and impregnation-H2 reduction) and tested as photocatalysts for methane conversion coupled with hydrogen production from water. The photocatalysts were characterized by Xray fluorescence, X-ray diffraction, UV-vis, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, and PL spectroscopy. The reactions were performed with the photocatalysts dispersed in water in a bubbling methane stream under UV-light illumination. The products were identified and quantified by gas chromatography (GC-FID/TCD/MSD). The main products formed were H2, C2H6, CO, and CO2 with minor quantities of C2H4, C3H8, and C4H10. The best performances were observed for the photocatalysts prepared with the nominal Au content of 0.1 wt% regardless of the method used. A production rate of about 100 mmol g−1 h−1 for C2H6 and 15 000 mmol g−1 h−1 for H2 was obtained. The Au content, nanoparticle sizes and interactions with Ga2O3 strongly influenced the photocatalytic activity.
  • Artigo IPEN-doc 29923
    Influência do tempo de síntese nas propriedades de híbridos PtRu/carbono preparados pelo método da carbonização hidrotérmica
    2023 - TUSI, MARCELO M.; POLANCO, NATALY S. de O.; VILLALBA, JUAN C.; ANAISSI, FAUZE J.; OLIVEIRA NETO, ALMIR; SPINACE, ESTEVAM V.
    Introdução: Eletrocatalizadores PtRu/C apresentam bons resultados para a eletro-oxidação do metanol. A atividade destes eletrocatalisadores é fortemente dependente do método de síntese. Adicionalmente, o uso de carbonos mesoporosos ou nanoestruturados aumentam o desempenho de eletrocatalisadores usados para a eletro-oxidação de álcoois. A carbonização hidrotérmica é uma alternativa para obter diferentes nanoarquiteturas sem envolver condições drásticas. Objetivos: Assim, este trabalho teve como objetivo avaliar a influência do tempo de síntese nas propriedades de híbridos PtRu/Carbono preparados pelo método da carbonização hidrotérmica. Métodos: Híbridos PtRu/Carbono foram preparados por carbonização hidrotérmica em diferentes tempos (6 h e 12 h). A celulose foi a fonte de carbono e agente redutor e H2PtCl6.6H2O e RuCl3.xH2O foram as fontes de metais e catalisadores do processo de carbonização. Os materiais foram tratados a 900 °C e caracterizados por espectroscopia por energia dispersiva de raios-X, termogravimetria, isotermas de B.E.T., difração de raios-X, microscopia eletrônica de transmissão e voltametria cíclica. A eletro-oxidação do metanol foi estudada por cronoamperometria. Resultados: O aumento de 6 para 12 h de síntese, aparentemente, resultou em aumento do tamanho médio de partículas, redução do volume de mesoporos e aumento da área superficial e do volume total de poros. A cronoamperometria da eletro-oxidação do metanol sobre os híbridos PtRu/Carbono indicaram uma maior eletroatividade para o material preparado em 6 h. Discussão: Provavelmente, a maior eletroatividade do material preparado em 6 h está associada ao menor tamanho de partícula, à estrutura de mesoporos e conteúdo de óxidos superficiais. Conclusões: Portanto, é possível afirmar que o tempo de síntese é um importante parâmetro que afeta as propriedades físico-químicas de híbridos metal/carbono obtidos pelo método da carbonização hidrotérmica.
  • Resumo IPEN-doc 29727
    Projeto e construção de um sistema de aquecimento por micro-ondas de baixo custo para avaliação de susceptores
    2022 - BRANDAO, ULISSES; SPINACE, ESTEVAM V.; SEKO, MURILO H.; FERREIRA, WILLIAM de P.
    Este trabalho consistiu no projeto e construção de um forno de micro-ondas de 2,45 GHz, destinado à avaliação de susceptores a serem utilizados como catalisadores, em temperaturas de 400 a 1.100 ºC. Sua construção baseou-se em simulações feitas em computador, seguida de testes e modificações para sua funcionalização.
  • Artigo IPEN-doc 29618
    Photocatalytic methane conversion over Pd/ZnO photocatalysts under mild conditions
    2023 - MACHADO, ARTHUR P.; CARMINATI, SAULO A.; JANUARIO, ELIANE R.; FERREIRA, PATRICIA S.; VAZ, JORGE M.; SPINACE, ESTEVAM V.
    Here, Pd nanoparticles supported on ZnO were prepared by the alcohol-reduction and the borohydride-reduction methods, and their efficiency towards the photocatalytic conversion of methane under mild conditions were evaluated. The resulting Pd/ZnO photocatalysts were characterized by X-ray fluorescence, X-ray diffraction, X-ray photoelectron spectroscopy, UV–Vis, and transmission electron microscopy. The reactions were performed with the photocatalysts dispersed in water in a bubbling stream of methane under UV-light illumination. The products formed were identified and quantified by gas chromatography (GC-FID/TCD/MSD). The principal products formed were C2H6 and CO2 with minor quantities of C2H4 and CO. No H2 production was observed. The preparation methods influenced the size and dispersion of Pd nanoparticles on the ZnO, affecting the performance of the photocatalysts. The best performance was observed for the photocatalyst prepared by borohydride reduction with 0.5 wt% of Pd, reaching a C2H6 production rate of 686 µmol·h−1·g−1 and a C2H6 selectivity of 46%.
  • Resumo IPEN-doc 29570
    Photocatalytic oxidation of methane coupling with hydrogen evolution from water over Au decorated Ga2O3 catalysts
    2022 - JANUARIO, ELIANE R.; VAZ, JORGE M.; SPINACE, ESTEVAM V.
    Methane is a major constituent of natural gases and is an important source of carbon and hydrogen for the chemical industry. However, CH4 is one of the most stable molecule and high reaction temperatures are required to transform CH4 into more valuable chemicals [1]. In this work, we investigated the use of β-Ga2O3 loaded with Au nanoparticles (0.1–1.0%) as photocatalysts that were prepared 3 different methods: pre-formed NNTS; in-situ; and H2 reduction. The materials were characterized by XRD, UV-Vis, TEM, and Raman. The reactions were performed on a photocatalytic reactor with Hg lamp (450W, UV/A/B/C). CH4 gas was bubbled into H2O, Au/Ga2O3 in suspension and the products were identified by GC-MS and quantified by GC-FID/TCD using calibration curves. C2H6, CO2, H2 with minor quantities of C2H4, C3H8, C4H10, and CO were produced. The best performance was observed for the photocatalyst prepared with 0.03% of Au that produced 112 mol.gcat-1h-1 of C2H6 and 16.500 mol.gcat-1h-1 of H2.
  • Resumo IPEN-doc 29568
    Development of noble metals/TiO2 photocatalysts for photocatalytic conversion of methane coupling with hydrogen evolution from water
    2022 - SILVAINO, PATRICIA F.; SPINACE, ESTEVAM V.; VAZ, JORGE M.
    Methane, the main component of natural gas (< 80%), is an expressive source of carbon and hydrogen, with large world reserves and can be used as raw material to produce petrochemicals and fuels; however, efficient CH4 conversion under mild conditions remains a challenge due to its low reactivity. In addition, the methane conversion coupled with water splitting, which is the purpose of this work, is quite interesting and desirable, due to the production of hydrogen in a more sustainable way. One of the alternative ways to convert CH4 under low temperatures is Heterogeneous Photocatalysis, which will be used in the present study. When a semiconductor photocatalyst absorbs light with a wavelength greater than or equal to its bandgap, electrons are photoexcited to the conduction band and holes (h+) are formed in the valence band, forming the so-called electron-hole pairs, which in turn can initiate various redox reactions (Figure 1). Solar Photocatalysis would be an ideal method to convert methane and produce hydrogen from water. In this project, photocatalysts with different compositions and morphologies will be developed based on noble metals nanoparticles (Pt, Pd, Au, Ag) supported on TiO2 P25. The final goal is to obtain more active photocatalysts to increase the quantum efficiency of the system.
  • Resumo IPEN-doc 29192
    Au/Ga2O3 photocatalysts for methane conversion coupling with hydrogen evolution from water
    2022 - JANUARIO, ELIANE R.; VAZ, JORGE M.; SPINACE, ESTEVAM V.
    Methane is a major constituent of natural gases and is an important source of carbon and hydrogen for the chemical industry. However, methane is one of the most stable molecule and high reaction temperatures are required to transform methane into more valuable and useful chemicals [1]. The use of solar energy and a photocatalyst would be an ideal method to convert methane in milder conditions.[1] Recently, it was reported the direct combination of hydrogen evolution from water and the methane conversion in a photocatalytic system over Pt/TiO2.[2] In this study, we investigated the use of β-Ga2O3loaded with different amounts of Au nanoparticles (0.1–1.0%) as photocatalysts that were prepared by impregnation of HAuCl4 solution onto a commercial β-Ga2O3 and reduction at 200 °C under hydrogen flow. The photocatalysts were characterized by X-ray diffraction (XRD), UV-Vis spectroscopy, Transmission Electron Microscopy (TEM), and Raman Spectroscopy. The photocatalytic reactions were performed on a commercial Ace photocatalytic reactor equipped with a mercury lamp (450W, UV/A/B/C). A steady stream of methane gas was bubbled into water containing the photocatalyst in suspension and the products were identified by GC-MS and quantified by GC-FID/TCD using calibration curves. The principal products formed were C2H6, CO2, and H2 with minor quantities of C2H4, C3H8, C4H10, and CO. The best performance was observed for the photocatalyst prepared with 0.1% of Au that produced 129 μmol.gcat -1h-1of C2H6 and 10,062 μmol.gcat -1h-1of H2.