resumo
In this work, we report a comparative study of Ni-based anode compositions, made of Cu and Co (40 and 80 mol %) and gadolinia-doped ceria (CGO) matrices, for application the dry reforming of methane (DRM) reaction using Solid Oxide Fuel Cells (SOFCs). The new compositions are synthesized by a one-step synthesis route, using citric acid as chelating agent, and characterized at three different stages: i) after synthesis, ii) after reduction, and iii) after DRM. X-ray diffraction (XRD) analysis combined with thermodynamic calculations is used to understand phase evolution along the different stages, revealing that complete solid solutions of NiCo- and NiCu-based alloys are formed after DRM reaction. Transmission Electron Microscopy (TEM) shows the formation of nanocrystalline powders, while surface area (SBET) measurements show higher values in the case of the NiCo-based samples. Moreover, the Co-containing compositions exhibit higher reducibility and stronger metal-ceramic interactions than the Cu-containing samples, according to the Temperature Programmed Reduction (TPR) results. Finally, DRM results demonstrate higher CO2 and CH4 conversions in the case of the Co-containing samples, as well as increased resistance towards carbon deposition, as confirmed by Thermogravimetric and Differential Scanning Calorimetry analyses (TG-DSC). Overall, the Co-based compositions are highly beneficial for their use as anodes for the CO2 reforming of methane in SOFCs.
palavras-chave
OXIDE FUEL-CELLS; MG-AL CATALYSTS; SYNGAS PRODUCTION; CARBON-DIOXIDE; BIMETALLIC CATALYSTS; NICKEL; BIOGAS; TEMPERATURE; CH4; PERFORMANCE
categoria
Materials Science, Ceramics
autores
Cesario, MR; Souza, GS; Loureiro, FJA; Araujo, AJM; Grilo, JPF; Aouad, S; Tidahy, HL; Macedo, DA; Fagg, DP; Gennequin, C; Abi-Aad, E
nossos autores
João Grilo
Investigador Júnioragradecimentos
This study was financed in part by the Coordenacao de Aperfeicoa-mento de Pessoal de Nivel Superior (CAPES/Brazil, Finance Code 001) . Francisco J. A. Loureiro and Duncan P. Fagg acknowledge the projects PTDC/CTM-CTM/2156/2020, PTDC/QUI-ELT/3681/2020, POCI-01-0145-FEDER-032241, UIDB/00481/2020 and UIDP/00481/2020-Fundacao para a Ciencia e a Tecnologia; and CENTRO-01-0145-FEDER-022083-Centro Portugal Regional Operational Programme (Cen-tro2020) , under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund. Francisco J. A. Loureiro also acknowledges FCT for the financial support with the reference CEE-CIND/02797/2020. Allan Araujo thanks the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq/Brazil, reference number 200439/2019-7) .