In this project we propose studies for the development of Ni and Co based catalysts, "reals" and "models" for steam reforming of ethanol (SRE), as well as the development of in situ methods of characterization. The effects variation of Co/Ni composition and metal loading in bimetallic systems will be evaluated regarding the control of carbon accumulation and the decreasing of methane formation during reforming reaction. The catalysts will be prepared by different techniques in order to obtain different particle sizes. It has been seen that these parameters (particle size and metallic composition) influences both the formation of methane (unlike in the point of view of H2 yield) as well as the carbon accumulation. It is observed the formation of a spinel M+2(M+3)2O4 in bimetallic Co-Ni catalysts and this mixed oxide once reduced can yield a Co-Ni alloy, according the literature data suggests. The alloy formation influences the carbon deposition on the catalyst surface during SRE, which can be assigned to changes in the electronic properties with Co addition on Ni, due to the shift in d-band center of the metals regarding to the Fermi level. Oxide species (MO) in the metallic nanoparticles surface (M0) can be formed under the SRE atmosphere. The oxi-reduction properties and density of oxide species on the catalyst surface might depend on the particles size and its electronic properties in the metal surface. These oxide species may help in the carbon oxidation formed during SRE in the metals surface, which would be represented by the reactions M0+ H2O MO + H2 e C-M0 + MO CO + 2M0. Thus, it is expected that the study of how the mentioned hey points affect the catalytic properties will lead to the understanding of reaction and consequently to stable catalysts for steam reforming of ethanol.
News published in Agência FAPESP Newsletter about the scholarship: