Zirconia-supported cobalt catalysts: activity and selectivity in NO reduction by CO

Resumo

Cobalt catalysts supported on tetragonal and monoclinic zirconia were prepared using a one-pot procedure through the incorporation of a Co3O4 colloidal suspension during the support synthesis and evaluated in the reaction of NO reduction by CO. A better dispersion of the active phase was obtained by this method when compared to the conventional impregnation one. Furthermore, the crystalline phase of zirconia in the supports had a crucial effect in the dispersion of the cobalt species, being that the pure tetragonal phase led to a higher dispersion of the active phase. The one-pot prepared tetragonal zirconia led to cobalt active species that consisted in well-dispersed small agglomerates of Co3O4 and Co2+ species as oxo-ions which displayed the best catalytic performance among the studied catalysts, with the highest NO conversion (75%) and high selectivity to N2 (85%) at 300 °C. These results show that the one-pot methodology employed in this work has a strong potential to produce suitable catalysts for the abatement of NOx emissions.

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LIMA, Thiago M. et al. Zirconia-supported cobalt catalysts: activity and selectivity in NO reduction by CO. ChemistrySelect, New York, v. 2, p. 11565-11573, 2017. DOI: 10.1002/slct.201702475. Disponível em: https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/slct.201702475. Acesso em: 25 maio 2023.