NEIVA, L. S.; http://lattes.cnpq.br/4948477421625867; NEIVA, Laédna Souto.
Résumé:
The aim of this work has been to synthesize cerium oxide catalysts doped
with copper, type Cei-xCux02, and evaluate their performance in the preferential
oxidation of CO reaction (PROX). The catalysts analyzed in this work were
obtained through two different synthesis methods, combustion reaction and
Pechini, without the need of performing a step of impregnation of the active
catalytic species. Thus, by means of both synthesis methods mentioned, were
obtained in a step synthesis single, catalysts with the composition Cei-xCux02,
where the value x in copper took the following values: 0, 0.1, 0.2 , 0.3, 0.4 and 0.5
mol. All samples synthesized catalysts were submitted to different techniques of
structural and physical characterizations, and catalytic evaluation, carried out
specifically in the PROX reaction in bench scale. By means the method of
synthesis of the combustion reaction was not possible to obtain structures single
phase Ce02 for all samples of catalysts with compositions containing the presence
of Cu as a dopant element. However, the catalysts synthesized by the Pechini
method, containing Cu as element dopant with concentrations up to 0.2 mol,
presented single phase structures composed by Ce02 . It was concluded that for
the synthesis of catalysts with composition Cei-xCux02 are not required
concentrations of Cu higher that 0.2 mol for the PROX reaction reach great
percentage, both in relation to CO conversion and in relation to selectivity, this
finding was observed for both synthesis methods used. However, the Pechini
method was better for carrying to obtainment of catalysts with structural
characteristics more easily controllable and with upper catalytic performance.
