Performance of new Pt and Pt-Cu on hydrotalcite-derived materials for NO_X storage/reduction

摘要

A series of Pt and Pt,Cu supported catalysts was prepared by impregnation of Mg-Al supports obtained from hydrotalcite-type (HT) precursor compounds calcined at different temperatures.These NO_x storage-reduction (NO_XSR) catalysts show improved performances in NO_x storage respect to Pt-Ba/Al_2O_3 NO_xSR catalysts at reaction temperatures lower than 473 K.These catalysts also show improved resistance to deactivation by SO_2.The co-presence of Pt and Cu (at different ratio Pt/Cu and using different impregnation methods) slightly worsens low temperature activity,but considerably promotes the resistance to deactivation after severe hydrothermal treatment and in presence of SO_2.The overall Pt-Cu/HT performances are thus higher than those of the Pt-Ba/Al_2O_3 Toyota-type NO_XSR catalysts.