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This research focuses on co-cations modified Cu-zeolite catalyst CuCe/SSZ-13. The NOx conversion and hydrothermal stability of fresh and aged Cu/SSZ-13 and CuCe/SSZ-13 were evaluated to conclude the impact of Ce on the zeolite stability and mechanism of NH3-SCR reaction. For fresh samples, CuCe/SSZ-13 exhibited more than 80% efficiency at 225 °C to 600 °C, and showed higher NOx conversion below 225 °C and above 450 °C than Cu/SSZ-13. For aged catalysts, CuCe/SSZ-13 exhibited higher efficiency at all test temperatures than Cu/SSZ-13, and exhibited over 80% conversion at 225 °C to 350 °C, whereas, that was only 250 °C to 300 °C over fresh Cu/SSZ-13 sample. Furthermore, the effect of co-cation Ce on the phase structure changes, acid sites, redox capacity, transformation of various Cu species, and framework stability of the samples were evaluated by several techniques, such as TPD, TPO, TPR, BET, and XRD.

In-cylinder thermochemical fuel reforming (TFR), which involves running one cylinder rich of stoichiometric and routing its entire exhaust back into the intake manifold, is an attractive method for improving engine performances. Compared with other hydrocarbon fuels, the chemical structure of methane is more stable owing to much shorter carbon chain. As ethanol contains hydroxyl in chemical structure, it potentially generates OH radical during the combustion. Therefore, adding ethanol into natural gas (NG) might help the thermochemical reforming process in engine cylinder. This paper focused on researching the effects of ethanol-NG combined in-cylinder TFR on engine performances, before which the effect of NG in-cylinder TFR was examined in detail. Cylinder #4 (TFR cylinder) was running rich and its cooled exhaust was coupled to the intake manifold of a four-cylinder engine during the experiments.