B. Pereda-Ayo, D. Divakar, R. López-Fonseca
Sep 1, 2009
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Influential Citations
17
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Journal
Catalysis Today
Abstract
Abstract The influence of platinum and barium precursors on the catalytic performance of monolithic Pt–Ba/Al 2 O 3 NO x storage catalysts was studied. The precursors used in the preparation were: tetraammineplatinum nitrate [Pt(NH 3 ) 4 (NO 3 ) 2 ] and hexachloroplatinic acid [H 2 Pt(Cl) 6 ] for incorporation of platinum by adsorption from solution (ion exchange); and barium acetate [Ba(CH 3 –COO) 2 ] and barium nitrate [Ba(NO 3 ) 2 ] for incorporation of barium by dry impregnation. The prepared samples were characterized by XRD, H 2 chemisorption and thermogravimetry, to determine the distribution and dispersion of the metallic phases. The catalytic activity of the prepared monolithic catalysts was tested for lean/rich NO x storage and reduction in a flow reactor using hydrogen as reducing agent. The catalyst prepared from tetraammineplatinum nitrate and barium acetate was the most active in the NO x storage during the lean period. NO x storage capacity (NSC) and selectivity were dependent with temperature. The higher NSC was obtained at temperature 330–350 °C. About 80% selectivity to nitrogen was achieved with catalysts prepared from tetraammineplatinum nitrate, versus 70% when the platinum was incorporated from hexachloroplatinic acid.