摘要
In this paper,CuO_(x)@Ag/CeO_(2) catalysts were synthesized by simple wet-chemical method and equal volume impregnation method.The obtained catalysts were subjected to soot temperature programmed oxidation(soot-TPO)activity tests and were further characterized by various techniques such as X-ray diffraction(XRD),transmission electron microscopy/high-resolution transmission electron microscopy(TEM/HR-TEM),N_(2) physisorption,X-ray photoelectron spectroscopy(XPS)and H_(2)-temperature programmed reduction(H_(2)-TPR).The results show that CuO_(x)@Ag/CeO_(2) synthesized presents well controlled core-shell structures,with nano-cube like Cu_(2)O as the core and Ag decorated polycrystalline CeO_(2) grafting layers as the shell.Such core-shell structured CuO_(x)@Ag/CeO_(2) can successfully construct a secondary oxygen delivery channel(CuO_(x)→CeO_(2)→Ag)to effectively transfer bulk oxygen of the catalyst to the soot,resulting in its excellent soot oxidation activity compared to CuO_(x)@CeO_(2).The potential benefiting effect by Ag introduction over Cu@Ag/Ce can be concluded as:(ⅰ)pumping lattice oxygen and accelerating gaseous O_(2) dissociation to generate significantly increased active surface oxygen content;(ⅱ)modulating a moderate surface oxygen vacancies concentration to maintain more highly active O_(2) species.
基金
Project supported by National Key R&D Program of China(2017YFC0211102)
Natural Science Foundation of the Jiangsu Higher Education Institutions of China(20KJB610005)
the Natural Science Foundation of Jiangsu Province(BK20201037)
Key Research and Development Program of Anhui Province(202104g01020006)
the Scientific Research Fund of Nanjing Institute of Technology(YKJ2019111,YKJ2019110)。
