CuO decorated vacancy-rich CeO2 nanopencils for highly efficient catalytic NO reduction by CO at low temperature

With the rapid development of transportation and vehicles, the elimination of NO x and CO has highly attracted public attention. In this work, vacancy-rich CeO 2 nanopencil supported CuO catalysts (CuO/CeO 2 -NPC) were successfully prepared for NO reduction by CO. Importantly, CeO 2 with nanopencil-like shape (CeO 2 -NPC) have been synthesis by solvothermal method for the first time. The physicochemical properties of all samples were studied in detail by combining the means of X-ray diffraction (XRD), Raman spectroscopy, electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), H 2 -temperature-programmed reduction (H 2 -TPR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N 2 physisorption (Brunauer–Emmett–Teller), and NO and CO temperature-programmed desorption (NO-TPD and CO-TPD) techniques. Compared with CeO 2 nanorods and nanoparticles supported CuO catalysts (CuO/CeO 2 -NR and CuO/CeO 2 -NP), the CuO/CeO 2 -NPC catalysts showed the highest catalytic activity, affording more than 90% NO conversion at 69 °C as well as excellent H 2 O tolerance at 150 °C, which is superior to catalysts previously reported. Characterization results indicated that the synergistic effect between the well-dispersed CuO and the CeO 2 nanopencil support enables a favorable electron transfer between these components and enhances the density of surface oxygen vacancies and Cu + species, which consequently accelerating the redox cycle. The results indicated that the morphology control of CeO 2 support could be an efficient way to evidently enhance the catalytic performance for NO + CO reaction.