Design efficient catalyst which can activate oxygen molecules or supply active oxygen species is a key challenge for soot abatement under the much lower concentration of oxygen from gasoline vehicle exhaust. Herein, combining with the advantages of both CeO-based oxide (CeO–ZrO–YO–LaO, CZ for short) and perovskite (LaMnO and LaFeO) in oxygen storage/release, two hybrids catalysts, CZ-LaMnO (LM) and CZ-LaFeO (LF), with more oxygen vacancies and enhanced lattice oxygen transport at lower temperatures due to the heterointerface effects have been successfully synthesized for soot oxidation. Combining with X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), oxygen temperature-programmed desorption (O-TPD) and Htemperature-programmed reduction (H-TPR), it was found that electrons transfer from Ce to Fe and an interfacial La diffusion from LM to CZ may have been occurred in LF-CZ and LM-CZ, respectively, which leads to the increased unsaturated sites and oxygen vacancies. More importantly, the obvious enhancement of active surface lattice oxygen transport at low temperatures due to interfacial interaction has also been demonstrated in LM-CZ, which highly promotes the soot oxidation. And consequently, 5LM-CZ (with 5 wt% content of LM) showed the highest soot conversion activity, whose (50 % soot conversion temperature) (379 °C) was lower than 5LF-CZ (395 °C) and CZ (401°C) at tight contact mode in 1 %O/N atmosphere, indicating that the activation of lattice oxygen at the interface plays an important role in soot oxidation. Furthermore, when further varying the content of LM in LM-CZ ( = 5 wt%, 10 wt%, 15 wt%, 20 wt%), it was found that 10LM-CZ, whose content of LM reached the monolayer dispersion capacity of CZ, exhibited the most abundant active surface lattice oxygen species due to the optimized interface area. As a result, 10LM-CZ displayed superior activity even than pure LM in both loose and tight contact with/without NO, indicating that the composite catalyst has a wide application environment. This work has a certain guiding significance for the utilization of heterointerface effect among different components to prepare effective soot oxidation catalyst with multi-components.

中文翻译：

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强调 CeO2 基氧化物和钙钛矿 (LaMnO3/LaFeO3) 之间的界面在产生烟灰氧化活性氧物质方面的关键作用


设计能够活化氧分子或提供活性氧物质的高效催化剂是在汽油车尾气中氧浓度低得多的情况下减少烟灰的关键挑战。在此，结合CeO基氧化物（CeO-ZrO-YO-La2O，简称CZ）和钙钛矿（LaMnO和LaFeO）在储/释放氧方面的优势，两种混合催化剂CZ-LaMnO（LM）和CZ -LaFeO (LF) 具有更多的氧空位，并且由于异质界面效应而在较低温度下增强了晶格氧传输，已成功合成用于烟灰氧化。结合X射线衍射（XRD）、高分辨率透射电子显微镜（HRTEM）、X射线光电子能谱（XPS）、氧气程序升温脱附（O-TPD）和H程序升温还原（H-TPR），研究发现，LF-CZ 和 LM-CZ 中可能分别发生了从 Ce 到 Fe 的电子转移以及从 LM 到 CZ 的界面 La 扩散，导致不饱和位点和氧空位增加。更重要的是，LM-CZ 还证明了由于界面相互作用而在低温下活性表面晶格氧传输的明显增强，从而极大地促进了烟灰氧化。因此，5LM-CZ（LM含量为5 wt%）表现出最高的烟灰转化活性，其（50%烟灰转化温度）（379 °C）低于5LF-CZ（395 °C）和CZ（401 °C）在1%O/N气氛中的紧密接触模式下，表明界面处晶格氧的活化在烟灰氧化中起着重要作用。 此外，当进一步改变LM-CZ中LM的含量（= 5 wt%、10 wt%、15 wt%、20 wt%）时，发现10LM-CZ的LM含量达到了单层分散能力由于优化的界面面积，CZ 表现出最丰富的活性表面晶格氧物种。结果表明，10LM-CZ在有/无NO的松散和紧密接触下均表现出比纯LM更优异的活性，表明该复合催化剂具有广泛的应用环境。该工作对于利用不同组分之间的异质界面效应制备高效的多组分烟灰氧化催化剂具有一定的指导意义。