Cobalt deposited on micro and nanometric structures of ceria and zirconia applied in diesel soot combustion.

M. ÁNGELES STEGMAYER; V. G. MILT; N. NAVASCUES; E. GAMEZ; S. IRUSTA; E.E. MIRÓ

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2020

1381-1169

Two series of shaped catalysts wereobtained, one of them from CeO2 and the other one from ZrO2,to which cobalt was added. On the one hand, ceria fibers prepared byelectrospinning exhibited greater catalytic activity for soot combustion, underloose contact and in the presence of NO, than those made by hydrothermalsynthesis. The deposition of low loads of cobalt (2 wt.%) resulted in apositive effect for soot combustion (maximum soot combustion rate, TM=360°C),whereas higher loadings (12 wt.%) did not result in a further improvement. Onthe other hand, cobalt catalysts supported on zirconia nanorods were preparedby hydrothermal synthesis. In comparison with the ceria catalysts, zirconiashowed a better catalytic activity when the cobalt load increased from 2 to 12wt.%, due to a better dispersion of cobalt on ZrO2. This is in linewith STEM and EDX results that indicated the presence of smaller aggregates of cobalton the zirconia surface. Among the ZrO2 catalysts studied, Co(12%)-ZrO2presented the best catalytic activity (TM=360°C), obtained underloose contact conditions and in the presence of NO. The activity of thecatalysts was thoroughly correlated with the characterization of the samples byXRD, SEM, EDX, STEM, LRS and XPS.