EDUARDO GUIMARAES CANDIDO
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Artigo IPEN-doc 25672 Ethanol steam reforming2019 - RODRIGUES, THENNER S.; SILVA, FELIPE A. e; CANDIDO, EDUARDO G.; SILVA, ANDERSON G.M. da; GEONMONOND, RAFAEL dos S.; CAMARGO, PEDRO H.C.; LINARDI, MARCELO; FONSECA, FABIO C.We reported herein a systematic investigation on how the nature of the support affected the catalytic performances of Rh nanoparticles. The prepared catalysts were denoted as Rh/MxOy, where M corresponded to Ce, Ti, Si, Zn, and Al, and Rh was Rh3+ reduction to Rh nanoparticles on the surface of oxides. This strategy was performed in a single step using urea as a mediator and in the absence of any other stabilizer or capping agent. The Rh nanoparticles displayed relatively similar sizes, shapes, and uniform distribution over the supports, differing only in terms of the nature of the support. This strongly affected the metal–support interaction between Rh nanoparticles and the respective oxides, leading to significant differences in their catalytic performances toward the ethanol steam reforming. Here, not only the catalytic activity (in terms of ethanol conversion) was affected, but both the selectivity and stability were also influenced by the nature of the oxide support. Interestingly, the reaction paths as well as the deactivation profile were completely changed as function of the employed support. Such differences were associated with differences in the oxygen storage, oxygen mobility, and acidity/basicity of the supports. We believe that our results can contribute to the development and understanding of Rh-supported catalysts for the applications toward gas-phase transformations such as the ethanol steam reforming reaction.Resumo IPEN-doc 25164 Nanoestrelas de óxido de zinco decorados com ouro e níquel para aplicações em catálise e reforma de etanol2018 - CANDIDO, EDUARDO G.; RODRIGUES, THENNER S.Artigo IPEN-doc 25045 Ni supported Ce0.9Sm0.1O2-δ nanowires2019 - RODRIGUES, THENNER S.; MOURA, ARTHUR B.L. de; SILVA, FELIPE A. e; CANDIDO, EDUARDO G.; SILVA, ANDERSON G.M. da; OLIVEIRA, DANIELA C. de; QUIROZ, JHON; CAMARGO, PEDRO H.C.; BERGAMASCHI, VANDERLEI S.; FERREIRA, JOAO C.; LINARDI, MARCELO; FONSECA, FABIO C.We reported herein the synthesis in high yields (> 97%) of Ce0.9Sm0.1O2-δ nanowires displaying well-defined shape, size, and composition by a simple, fast, and low-cost two-step hydrothermal method. The Ce0.9Sm0.1O2-δ nanowires synthesis was followed by the wet impregnation of Ni without the utilization of any stabilizing agent. The Ni/Ce0.9Sm0.1O2-δ nanowires showed higher surface area, high concentration of oxygen vacancies at surface, and finely dispersed Ni particles with significantly higher metallic surface area as compared with catalysts prepared from commercial materials with similar compositions. Such unique and improved properties are reflected on the catalytic performance of the Ni/Ce0.9Sm0.1O2-δ nanowires towards ethanol steam reforming. The nanowires exhibited high yields for hydrogen production (∼60% of selectivity) and an exceptional stability with no loss of activity after 192 h of reaction at 550 °C. The reported results provide insights and can inspire highyield production of nanostructured catalysts displaying controlled and superior properties that enable practical applications in heterogeneous catalysis.