Lean NOx reduction on LNT-SCR dual-layer catalysts by H2 and CO

► CO inhibition of LNT mitigated by adding ceria and adding top layer of SCR. ► Ceria zoning in LNT layer exhibits high NOx conversion over wide temperature range. ► PGM loading in the LNT layer can be reduced by increasing the SCR loading. ► NOx conversion is improved by optimizing the lean-rich cycle ratio and duration.