A lean NOx trap (LNT) based emission control system typically consists of a LNT catalyst for NOx reduction and CO/HC oxidation and a catalyzed soot filter (CSF) for particulate filtration and CO/HC oxidation. During LNTs operation, it is required that sulfur compounds bound to the catalyst surface must be periodically removed in a reducing environment to recover the NOx storage sites. However, this desulfation process produces high levels of H2S emission, which must be suppressed. A series of catalyzed soot filters has been investigated for H2S suppression, and CuO based filters were found to be very efficient in converting H2S to SO2. Only 0.05 g/in(3) bulk CuO can convert 500 ppm H2S to SO2 with 100% efficiency at GHSV = 34,000 h(-1) after a high temperature aging treatment (800 degrees C/16 h with 10% H2O). However, CuO was found to severely poison the precious metal (PGM) functions in the filter, dramatically reducing its CO/HC oxidation activity. The degree of poisoning is proportional to the CuO loading and also related to the proximity between CuO and the PGM within the filter microstructure. A zoned coating approach, where CuO and PGM occupy two non-overlapping zones in the axial direction, has been systematically investigated with both laboratory reactor and engine tests. The zoned H2S-CSFs, with CuO in the front of the filter and the PGM in the rear, were demonstrated to be effective catalysts that can fulfil both H2S suppression and CO/HC oxidation requirements. (C) 2016 Elsevier B.V. All rights reserved.