Development of bimetallic Ni-Co nanoparticles catalysts for hydrogen production. Study of the cooperative effect and its influence on carbon accumulation.

ROMERO CASTRO LETICIA DEL CARMEN; BARROSO MARIANA NOELIA

Simposio; Simposio para Estudiantes PhD ?Materiales para Energía, Ambiente y Salud?; 2022

Organizado por la Asociación de Universidades Grupo Montevideo (AUGM) y el Centro Universitario de Baviera para América Latina (BAYLAT)

Ni–Co catalysts supported on MgAl2O4–CeO2 were prepared by the sol–gel method. The solids were calcined under a reducing atmosphere to obtain Ni and/or Co active sites. The influence of cobalt content (1, 3 and 5% w/w) and impregnation sequence on the bimetallic catalysts containing 8% w/w Ni was studied. The catalysts were characterized by TG, FTIR, SBET, AAS, XRD, TPR, TEM, EELS, EFTEM, TPO and SEM. XRD patterns of the reduced samples did not reveal the presence of Ni nor Co, nor the possible formation of a metallic alloy, which suggests that metallic crystallite sizes are smaller than the detection limit of the technique. HRTEM and EELS analysis showed the presence of Co and Ni nanoparticles smaller than 20 nm. XPS spectra revealed the presence of Co0 and Ni0. In addition, in the Ce 3d region, peaks corresponding to Ce4+ and Ce3+ were observed. The catalysts were evaluated in the ethanol steam reforming reaction at 650 °C for 7 h. The results showed that the catalytic activity and the H2 selectivity are favored in bimetallic catalysts. The main reaction products were H2, CO2, CO and lower content of CH4, being the hydrogen selectivity being greater than 80%. To achieve the proposed objectives, another synthesis method is being studied. In addition, we continue to work in collaboration with CNEA-Bariloche to perform HRTEM and EELS. The results have been presented in scientific meetings and in a publication.