Development of monolithic catalysts with low noble metal content for diesel vehicle emission control

摘要

The chemical composition of the catalyst containing Mn–Al–O and Pt has been developed on the basis of the synergetic effect of Pt and manganese oxides observed in the HC and CO oxidation reactions. This effect allows decreasing the Pt loading to 0.70 g/L in the catalytic systems of diesel engine exhaust gases and provides high activity in low temperature oxidation of light and heavy hydrocarbons, and high thermal stability. It has been found that the catalytic activity of Pt–Mn–Al monolithic catalysts in butane oxidation and DIESEL tests depends on the Pt precursor and Pt loading. At similar Pt loadings (1.06 g/L), the catalytic activity increases in the order H2PtCl6~H2[Pt(OH)6] < Pt(NO2)2(NH3)2. When one Pt precursor is used, the catalytic performance improves with Pt loading increase from 0 to 1.06 g/L, and being nearly constant at higher Pt loading (2.65 g/L).